1000 (number)

Natural number 3 1,000 Thousand Chiliad 1000 (disambiguation) and Chiliarchy January 2023 1000 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 125, 200, 250, 500, 1000 M, m, ↀ ↀ chilia milli Tamil ௲ Chinese 千 Punjabi ੧੦੦੦ Devanagari १००० Armenian Ռ Egyptian hieroglyph 𓆼 thousand 1000 1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000. A group of one thousand units is sometimes known, from Ancient Greek, as a chiliad.https://www.merriam-webster.com/dictionary/chiliad chiliad Merriam-Webster A period of one thousand years may be known as a chiliad or, more often from Latin, as a millennium. The number 1000 is also sometimes described as a short thousand in medieval contexts where it is necessary to distinguish the Germanic concept of 1200 as a long thousand. It is the first 4-digit integer. Notation The decimal representation for one thousand is 1000—a one followed by three zeros, in the general notation; 1 × 103—in engineering notation, which for this number coincides with: 1 × 103 exactly—in scientific normalized exponential notation; 1 E+3 exactly—in scientific E notation. The SI prefix for a thousand units is "kilo-", abbreviated to "k"—for instance, a kilogram or "kg" is a thousand grams. This is sometimes extended to non-SI contexts, such as "ka" (kiloannum) being used as a shorthand for periods of 1000 years. In computer science, however, "kilo-" is used more loosely to mean 2 to the 10th power (1024 or 210). In the SI writing style, a non-breaking space can be used as a thousands separator, i.e., to separate the digits of a number at every power of 1000. Multiples of thousands are occasionally represented by replacing their last three zeros with the letter "K" or "k": for instance, writing "$30k" for $30,000 or using "Y2K" to denote the Year 2000 computer problem. A thousand units of currency, especially dollars or pounds, are colloquially called a grand. In the United States, this is sometimes abbreviated with a "G" suffix. In mathematics A chiliagon is a 1000-sided polygon.A195163 1000-gonal numbers: a(n) equal to n*(499*n - 498) Numbers in the range 1001–1999 1001 to 1099 1001 1001 (number) 1002 1002 (number) 1004 1004 = 22 × 251. It is a heptanacci number.A122189 Heptanacci numbers 1009 1009 is the smallest four-digit prime, a Lucky prime, and Chen prime. It is palindromic in bases 11, 15, 19, 24 and 28: (83811, 47415, 2F219, 1I124, 18128). 1011 1011 = 3 × 337. It is a Harshad number in bases 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 (and 202 other bases). It is the largest natural number n such that 2n contains 101 and does not contain 11011. There are 1011 partitions of 1 into reciprocals of positive integers <= 16 Egyptian fraction.A020473 Egyptian fractions: number of partitions of 1 into reciprocals of positive integers <= n 1013 1013 is a prime number, a Sophie Germain prime,A005384 Sophie Germain primes p: 2p+1 is also prime and a centered square number,A001844 Centered square numbers 1016 1016 = 23 × 127. It is stella octangula number and a member of the Mian–Chowla sequence.A005282 Mian-Chowla sequence There are 1016 surface points on a cube with edge-length 14.A005897 6*n^2 + 2 for n > 0 1019 1019 is a Sophie Germain prime, a safe prime,A005385 Safe primes p: (p-1)/2 is also prime and a Chen prime. 1021 1021 is a Lucky prime and a twin prime with 1019. 1023 1023 (number) 1024 1024 (number) 1025 1025 = 52 × 41. It is a Jacobsthal-Lucas number and the hypotenuse of a primitive Pythagorean triangle. It is a Proth number because 1025 = 210 + 1. It is a member of the Moser–de Bruijn sequence because its base-4 representation (1000014) contains only digits 0 and 1, or equivalently, it's a sum of distinct powers of 4 (45 + 40). 1028 1028 = 22 × 257. It is sum of totient function for first 58 integers. 1029 There are 1029 primes <= 213.A007053 Number of primes <= 2^n 1031 1031 is a prime number, a Sophie Germain prime, a super-prime, and a Chen prime. It is the exponent and number of ones for the fifth base-10 repunit prime.A004023 Indices of prime repunits: numbers n such that 11...111 (with n 1's)... is prime 1033 1033 is a prime number and an emirp. It forms a twin prime pair with 1031. 1035 1035 = 32 × 5 × 23. It is a hexagonal numberA000384 Hexagonal numbers and the 45th triangular number.A000217 Triangular numbers 1039 1039 is a Chen prime and a Lucky prime. There are 1039 partitions of 30 that do not contain 1 as a part.A002865 Number of partitions of n that do not contain 1 as a part 1040 1040 = 24 × 5 × 13. There are 1040 pieces that could be seen in a 6 × 6 × 6 × 6 Rubik's Tesseract. 1046 1046 = 2 × 523. It is a coefficient of f(q), the 3rd order mock theta function.A000025 Coefficients of the 3rd-order mock theta function f(q) 1049 1049 is a prime number, a Sophie Germain prime, a highly cototient number,A100827 Highly cototient numbers: records for a(n) in A063741 and a Chen prime. 1051 1051 is a prime number, a centered pentagonal number,A005891 Centered pentagonal numbers and a centered decagonal number. 1056 1056 = 25 × 3 × 11. It is a pronic number.A002378 Oblong (or promic, pronic, or heteromecic) numbers 1060 1060 = 22 × 5 × 53. It is the sum of the first twenty-five primes from 2 through 97 (the number of primes less than 100)A007504 Sum of the first n primes and the sixth sum of 10 consecutive primes, starting with 23 through 131.A127337 Numbers that are the sum of 10 consecutive primes 1061 1061 is a prime number, an emirp, and a twin prime with 1063. There are 1061 prime numbers between 1000 and 10000 (or, number of four-digit primes in decimal representation).A006879 Number of primes with n digits. 1063 1063 is a prime number, a super-prime, a twin prime with 1061, and the sum of seven consecutive primes (137 + 139 + 149 + 151 + 157 + 163 + 167) 1069 1069 is a prime number and an emirp.A006567 Emirps (primes whose reversal is a different prime) 1076 1076 = 22 × 269. There are 1076 strict trees weight 11.A273873 Number of strict trees of weight n 1078 1078 = 2 × 72 × 11. It is an Euler transform of negative integers.A073592 Euler transform of negative integers 1080 1080 = 23 × 33 × 5. It is a pentagonal numberA000326 Pentagonal numbers and a largely composite number.A067128 Ramanujan's largely composite numbers 1081 1081 = 23 × 47. It is the 46th triangular number and a member of Padovan sequence.A000931 Padovan sequence 1086 1086 = 2 × 3 × 181. It is a Smith numberA006753 Smith numbers and the sum of totient function for the first 59 integers. 1087 1087 is a prime number, a super-prime, a cousin prime, and a lucky prime.A031157 Numbers that are both lucky and prime 1089 1089 (number) 1091 1091 is a prime number, a cousin prime, and a twin prime with 1093. 1093 1093 is a twin prime with 1091. Together with 1091 and 1097, it forms a prime triplet. It is a happy prime and a starA003154 Centered 12-gonal numbers. Also star numbers prime. It is also the smallest Wieferich prime. 1093 is a repunit prime in base 3 because: 1097 1097 is a prime number, an emirp, and a Chen prime. 1100 to 1199 1102 1102 = 2 × 19 × 29. It is the sum of the totient function for the first 60 integers. 1103 1103 is a prime number, a Sophie Germain prime, and a balanced prime.A006562 Balanced primes 1104 1104 = 24 × 3 × 23. It is a Keith numberA007629 Repfigit (REPetitive FIbonacci-like diGIT) numbers (or Keith numbers) 1105 1105 (number) 1109 1109 is a Chen prime. 1113 1113 = 3 × 7 × 53. There are 1113 strict partitions of 40.A000009 Expansion of Product_{m > 0} (1 + x^m); number of partitions of n into distinct parts; number of partitions of n into odd parts 1117 1117 is a Chen prime. There are 1117 diagonally symmetric polyominoes with 16 cells.A006748 Number of diagonally symmetric polyominoes with n cells 1118 1118 = 2 × 13 × 43. There are 1118 unimodular 2 × 2 matrices having all terms in {0,1,...,21}.A210000 Number of unimodular 2 X 2 matrices having all terms in {0,1,...,n} 1119 1119 = 3 × 373. There are 1119 bipartite graphs with 9 nodes.A033995 Number of bipartite graphs with n nodes 1122 1122 = 2 × 3 × 11 × 17. It is a pronic number. 1123 1123 is a balanced prime. 1126 1126 = 2 × 563. There are 1126 2 × 2 non-singular integer matrices with entries from {0, 1, 2, 3, 4, 5}.A062801 Number of 2 X 2 non-singular integer matrices with entries from {0,...,n} 1127 1127 = 72 × 23. It is the maximum number of pieces that can be obtained by cutting an annulus with 46 cuts.A000096 n*(n+3)/2 1128 1128 = 23 × 3 × 47. It is the 47th triangular number and the 24th hexagonal number. 1128 is the dimensional representation of the largest vertex operator algebra with central charge of 24, D24.Van Ekeren Jethro Lam Ching Hung Möller Sven Shimakura Hiroki Schellekens' list and the very strange formula Advances in Mathematics 380 Elsevier Amsterdam 2021 107567 10.1016/j.aim.2021.107567 free 4200469 1492.17027 218870375 2005.12248 1151 is the first prime number following a prime gap of 22.https://oeis.org/A000101 Sloane's A000101 : Increasing gaps between primes (upper end) The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-07-10 It is also a Chen prime. 1152 1152 = 27 × 32. It is a highly totient number,https://oeis.org/A097942 Sloane's A097942 : Highly totient numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 a 3-smooth number, and an Achilles number. 1153 1153 is a super-prime and a Proth prime.https://oeis.org/A080076 Sloane's A080076 : Proth primes The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1159 1159 = 19 × 61. It is a centered octahedral numberA001845 Centered octahedral numbers (crystal ball sequence for cubic lattice) 2022-06-02 and a member of the Mian–Chowla sequence. 1160 1160 = 23 × 5 × 29. It is an octagonal number.A000567 Octagonal numbers: n*(3*n-2). Also called star numbers 1161 1161 = 33 × 43. It is the sum of the first twenty-six primes. 1162 1162 = 2 × 7 × 83. It is the sum of the totient function for the first 61 integers and a pentagonal number. 1163 1163 is a Chen prime. Legendre's conjecture 1164 1164 = 22 × 3 × 97. There are 1164 chains of multisets that partition a normal multiset of weight 8, where a multiset is normal if it spans an initial interval of positive integersA055887 Number of ordered partitions of partitions 1169 1169 = 7 × 167. It is a highly cototient number 1171 1171 is a super-prime.April 2026 1173 1173 = 3 × 17 × 23. There are 1173 simple triangulations on a plane with 9 nodes.https://oeis.org/A000256 A000256 - OEIS oeis.org 1174 1174 = 2 × 587. There are 1174 widely totally strongly normal compositions of 16. A332337. 1175 1175 = 52 × 47. It is the maximum number of pieces that can be obtained by cutting an annulus with 47 cuts. 1176 1176 = 23 × 3 × 72. It is the 48th triangular number. 1178 1178 = 2 × 19 × 31. There are 1178 surface points on a cube with edge-length 15. 1179 1179 = 32 × 131. There are 1179 different permanents of binary 7 by 7 matrices.https://number.academy/1179 1179 (number) The encyclopedia of numbers 1182 1182 = 2 × 3 × 197. There are 1182 necklaces possible with 14 beads of 2 colors (that cannot be turned over).https://oeis.org/A000031 A000031 - OEIS oeis.org 1184 1184 = 25 × 37. It is an amicable number with 1210.Number Story: From Counting to Cryptography https://archive.org/details/numberstoryfromc00higg_612 limited Higgins Peter 2008 Copernicus New York 978-1-84800-000-1 61 1186 1186 = 2 × 593. There are 1186 diagonally symmetric polyominoes with 15 cells. 1187 1187 is a safe prime, a Stern prime,https://oeis.org/A042978 Sloane's A042978 : Stern primes The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 a balanced prime, and a Chen prime. 1190 1190 = 2 × 5 × 7 × 17. It is a pronic number. Building a 28-tier house of cards requires 1190 cards.A005449 Second pentagonal numbers: n*(3*n + 1)/2 1191 1191 = 3 × 397 = 352 - 35 + 1 = H35, the 35th Hogben number.A002061 Central polygonal numbers: n^2 - n + 1 1192 1192 = 23 × 149. It is the sum of the totient function for the first 62 integers. 1193 1193 is a Chen prime. 41193 - 31193 is prime. 1198 1198 = 2 × 599. It is a centered heptagonal number.A069099 Centered heptagonal numbers 1200 to 1299 1200 1200 = 24 × 3 × 52. There are 1200 households in the Nielsen ratings sample.Meehan, Eileen R., Why TV is not our fault: television programming, viewers, and who's really in control Lanham, MD: Rowman & Littlefield, 2005 1200 is known as the long thousand or ten "long hundreds" of 120 each. It is the traditional reckoning of large numbers in Germanic languages. 1201 1201 is a super-prime, a centered square number, and a centered decagonal number. 1202 1202 = 2 × 601. There are a maximum of 1202 regions when the plane is divided by 25 ellipses.A051890 2*(n^2 - n + 1) 1203 1203 = 3 × 401. It is the smallest number greater than 1000 in the coordinating sequence for the (2,6,∞) tiling of the hyperbolic plane.https://oeis.org/A265070 A265070 - OEIS oeis.org 1204 1204 = 22 × 7 × 43. It is the magic constant for a 7 × 7 × 7 magic cube.https://number.academy/1204 1204 (number) The encyclopedia of numbers 1205 1205 = 5 × 241. There are 1205 partitions of 28 such that the number of odd parts is a partA240574 Number of partitions of n such that the number of odd parts is a part 1207 1207 = 17 × 71. It is a composite de Polignac number.A098237 Composite de Polignac numbers 1208 1208 = 23 × 151. There are 1208 strict chains of divisors starting with the superprimorial A006939(3).A337070 Number of strict chains of divisors starting with the superprimorial A006939(n) 1210 1210 = 2 × 5 × 112. It is an amicable number with 1184Higgins, ibid. and a Self-descriptive number. 1211 1211 = 7 × 173. It is a composite de Polignac number 1212 1212 = 22 × 3 × 101 = , where is the number of partitions of .A000070 Sum_{0..n} A000041(k) 1213 1213 is a prime number and an emirp. 1214 1214 = 2 × 607. It is a spy number and the sum of the first 39 composite numbers.A053767 Sum of first n composite numbers 1215 1215 = 35 × 5. There are 1215 edges in the hexagonal triangle T(27)A140091 3*n*(n + 3)/2 1216 1216 = 26 × 19. It is a nonagonal numberhttps://oeis.org/A001106 Sloane's A001106 : 9-gonal (or enneagonal or nonagonal) numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1217 1217 is a super-prime and a Proth prime. 1219 1219 = 23 × 53. It is a centered triangular numberA005448 Centered triangular numbers: 3n(n-1)/2 + 1 and a zero of Mertens function. 1220 1220 = 22 × 5 × 61. It is a zero of Mertens function. There are 1220 binary vectors of length 16 containing no singletons.A006355 Number of binary vectors of length n containing no singletons 1222 1222 = 2 × 13 × 47. It is a hexagonal pyramidal number. 1223 1223 is the 200th prime number. It is also a Sophie Germain prime and a balanced prime. 1224 1224 = 23 × 32 × 17. There are 1224 edges in the join of two cycle graphs, both of order 34.n*(n+2) 1225 1225 = 52 × 72 = 352. It is the smallest number greater than 1 to be a triangular number, a square number and a hexagonal number.https://oeis.org/A001110 Sloane's A001110 : Square triangular numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 It is the second square triangular number greater than 1.A046177 - OEIS https://oeis.org/A046177 2024-12-18 oeis.org It is the 49th triangular number, the 35th square number, the 25th hexagonal number, a centered octagonal number,https://oeis.org/A016754 Sloane's A016754 : Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 a 29-gonal number,A303815 Generalized 29-gonal (or icosienneagonal) numbers a 60-gonal number,A249911 60-gonal (hexacontagonal) numbers and a 124-gonal number. It is the sum of 5 consecutive odd cubes: 1225 = 13 + 33 + 53 + 73 + 93. 1226 1226 = 2 × 613. There are 1226 rooted identity trees with 15 nodes.https://oeis.org/A004111 A004111 - OEIS oeis.org 1228 1228 = 22 × 307. It is the sum of the totient function for the first 63 integers. 1229 1229 is a Sophie Germain prime and an emirp. There are 1229 primes less than 10,000. 1230 1230 = 2 × 3 × 5 × 41 = T(9, 6), the Mahonian number.A008302 Triangle of Mahonian numbers T(n,k): coefficients in expansion of Product{0..n-1} (1 + x + ... + x^i), where k ranges from 0 to A000217(n-1). Also enumerates permutations by their major index 1231 1231 is a prime number and an emirp. 1232 1232 = 24 × 7 × 11. There are 1232 labeled ordered set of partitions of a 7-set into odd parts.https://oeis.org/A006154 A006154 - OEIS oeis.org 1234 1234 (number) 1240 1240 = 23 × 5 × 31. It is a square pyramidal number.A000330 Square pyramidal numbers 1241 1241 = 17 × 73. It is a centered cube numberhttps://oeis.org/A005898 Sloane's A005898 : Centered cube numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 and a spy number. 1243 1243 = 11 × 113. It is a composite de Polignac number. 1244 1244 = 22 × 311. There are 1244 complete partitions of 25.A126796 Number of complete partitions of n 1245 1245 = 3 × 5 × 83. There are 1245 labeled spanning intersecting set-systems on 5 vertices.oeis.org/A305843 1247 1247 = 29 × 43. It is a pentagonal number. 1249 1249 is a prime number, an emirp, and a trimorphic number.https://oeis.org/A033819 Sloane's A033819 : Trimorphic numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1257 1257 = 3 × 419. There are 1257 lattice points inside a circle of radius 20.A000328 1259 1259 is a prime number and a highly cototient number. 1260 1260 = 22 × 32 × 5 × 7. It is a pronic number, the smallest vampire number,https://oeis.org/A014575 Sloane's A014575 : Vampire numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 the 16th highly composite number,https://oeis.org/A002182 Sloane's A002182 : Highly composite numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 and the sum of the totient function for the first 64 integers. There are 1260 strict partitions of 41. 1261 1261 = 13 × 97. It is a star number and a zero of Mertens function. 1264 1264 = 24 × 79. It is the sum of the first 27 primes. 1265 1265 = 5 × 11 × 23. There are 1265 rooted trees with 43 vertices in which vertices at the same level have the same degree.A003238 Number of rooted trees with n vertices in which vertices at the same level have the same degree 1266 1266 = 2 × 3 × 211. It is a centered pentagonal number and a zero of Mertens function. 1269 1269 = 33 × 47. Completing 11 revolutions in the Spiral of Theodorus requires 1269 triangles.A072895 Least k for the Theodorus spiral to complete n revolutions 1275 1275 = 3 × 52 × 17. It is the 50th triangular number. 1276 1276 = 22 × 11 × 29. There are 1276 irredundant sets in the 25-cocktail party graph.A084849 1 + n + 2*n^2 1277 1277 is a prime number. It is the start of a prime constellation of length 9 (a "prime nonuple"). 1278 1278 = 2 × 32 × 71. There are 1278 Narayana's cows and calves after 20 years.A000930 Narayana's cows sequence 1279 1279 is a prime number and a Mersenne prime exponent. 1280 1280 = 28 × 5. There are 1280 parts in all compositions of 9.A001792 (n+2)*2^(n-1) 1281 1281 = 3 × 7 × 61. It is an octagonal number. 1283 1283 is a safe prime. 1284 1284 = 22 × 3 × 107 = 641 + 643, the sum of a twin prime pair.A054735 Sums of twin prime pairs 1285 1285 = 5 × 257. There are 1285 free nonominoes. 1286 1286 = 2 × 643. There are 1286 inequivalent connected planar figures that can be formed from five 1 X 2 rectangles (or dominoes) such that each pair of touching rectangles shares exactly one edge, of length 1, and the adjacency graph of the rectangles is a tree.A216492 Number of inequivalent connected planar figures that can be formed from n 1 X 2 rectangles (or dominoes) such that each pair of touching rectangles shares exactly one edge, of length 1, and the adjacency graph of the rectangles is a tree 1288 1288 = 23 × 7 × 23. It is a heptagonal number.A000566 Heptagonal numbers (or 7-gonal numbers): n*(5*n-3)/2 1289 1289 is Sophie Germain prime and a twin prime with 1291. 1289 is a deficient number because the sum of all its positive divisors (except itself) totals less than 1289. 1289 is an evil number because it has an even number of 1's contained in its binary expansion. 1291 1291 is a twin prime with 1289. 1296 1296 = 24 × 34 = 64 = 362. It is the sum of the cubes of the first eight positive integers: 13 + 23 + 33 + 33 + 43 + 53 + 63 + 73 + 83 = 1296. There are 1296 rectangles on a normal 8 × 8 chessboard. There are 1296 combinations of 2 alphanumeric characters. 1297 1297 is a super-prime, a pinwheel number,A059993 Pinwheel numbers: 2*n^2 + 6*n + 1 and a zero of Mertens function. 1300 to 1399 1300 1300 = 22 × 52 × 13. It is a zero of Mertens function and the smallest even odd-factor hyperperfect number. It is the sum of the first 4 fifth powers: 1300 = 15 + 25 + 35 + 45. 1301 1301 is a prime number and a centered square number. There are 1301 trees with 13 unlabeled nodes.A000055 Number of trees with n unlabeled nodes 1306 1306 = 2 × 653. It is a centered triangular number. 1307 1307 is a safe prime. 1308 1308 = 22 × 3 × 109. It is the sum of the totient function for the first 65 integers. 1312 1312 = 25 × 41. It is a member of the Mian-Chowla sequence. 1319 1319 is a safe prime. 1325 1325 = 52 × 53. It is a Markov numberhttps://oeis.org/A002559 Sloane's A002559 : Markoff (or Markov) numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 and a centered tetrahedral number.A005894 Centered tetrahedral numbers 1326 1326 = 2 × 3 × 13 × 17. It is the 51st triangular number and a hexagonal number. 1327 1327 is the smallest prime number preceding a prime gap of 34. 1328 1328 = 24 × 83. It is the sum of the totient function for the first 66 integers. 1330 1330 = 2 × 5 × 7 × 19. It is a tetrahedral number.https://oeis.org/A000292 Sloane's A000292 : Tetrahedral numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 It forms a Ruth–Aaron pair with 1331 under second definition. 1331 1331 = 113. It is a centered heptagonal number. It forms a Ruth–Aaron pair with 1330 under second definition. 1335 1335 = 3 × 5 × 89. It is a pentagonal number. 1342 1342 = 2 × 11 × 61 = .A024916 Sum_1^n sigma(k) 1346 1346 = 2 × 673. There are 1346 locally disjointed rooted trees with 10 nodes.https://oeis.org/A316473 A316473 - OEIS oeis.org 1350 1350 = 2 × 33 × 52. It is a nonagonal number. 1361 1361 is first prime number following a prime gap of 34 and the 3rd Mills' prime. It is a centered decagonal number 1364 1364 = 22 × 11 × 31. It is a Lucas number.A000032 Lucas numbers: L(n-1) + L(n-2) 1365 1365 = 3 × 5 × 7 × 13. It is a pentatope number.https://oeis.org/A000332 Sloane's A000332 : Binomial coefficient binomial(n,4) = n*(n-1)*(n-2)*(n-3)/24 The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1367 1367 is a safe prime and a balanced prime. It is the sum of three, nine, and eleven consecutive primes: (449 + 457 + 461, 131 + 137 + 139 + 149 + 151 + 157 + 163 + 167 + 173, and 101 + 103 + 107 + 109 + 113 + 127 + 131 + 137 + 139 + 149 + 151), 1371 1371 = 3 × 457. It is the sum of the first 28 primes. 1377 1377 = 34 × 17. It is the maximal number of pieces that can be obtained by cutting an annulus with 51 cuts 1378 1378 = 2 × 13 × 53. It is the 52nd triangular number 1379 1379 = 7 × 197. It is the magic constant of n × n normal magic square and n-queens problem for n = 14. 1380 1380 = 22 × 3 × 5 × 23. There are 1380 8-step mappings with 4 inputs.A005945 Number of n-step mappings with 4 inputs 1381 1381 is a prime number and a centered pentagonal number. 1384 1384 = 23 × 173 = 1385 1385 = 5 × 277. It is an up/down number.A000111 Euler or up/down numbers: e.g.f. sec(x) + tan(x) 1387 1387 = 19 × 73. It is the 5th Fermat pseudoprime of base 2,https://oeis.org/A001567 Sloane's A001567 : Fermat pseudoprimes to base 2 The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 the 22nd centered hexagonal number, the 19th decagonal number,https://oeis.org/A001107 Sloane's A001107 : 10-gonal (or decagonal) numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 and the second Super-Poulet number.https://oeis.org/A050217 Sloane's A050217 : Super-Poulet numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1388 1388 = 22 × 347. Because 1388 = 4 × 192 - 3 × 19 + 1, is on the x-axis of Ulams spiral.A054552 4*n^2 - 3*n + 1 1394 1394 = 2 × 17 × 41. It is the sum of the totient function for the first 67 integers. 1395 1395 = 32 × 5 × 19. It is a vampire number and a member of the Mian–Chowla sequence 1396 1396 = 22 × 349. It is a centered triangular number. 1399 1399 is a prime number and an emirp.A109308 Lesser emirps (primes whose digit reversal is a larger prime) 1400 to 1499 1403 1403 = 23 × 61. It is the smallest number x such that M(x) = 11, where M() is Mertens functionA051400 Smallest value of x such that M(x) equals n, where M() is Mertens's function A002321 1404 1404 = 22 × 32 × 13. It is a heptagonal number. 1405 1405 = 5 × 281 = 262 + 272 = 72 + 82 + ... + 162. It is a centered square number 1406 1406 = 2 × 19 × 37. It is a semi-meandric number.https://oeis.org/A000682 Sloane's A000682 : Semimeanders The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1409 1409 is a super-prime, a Sophie Germain prime, and a Proth prime. 1410 1410 = 2 × 3 × 5 × 47. It is the denominator of the 46th Bernoulli numberA002445 Denominators of Bernoulli numbers B_{2n} 1418 1418 = 2 × 709. It is the smallest number x such that M(x) = 13, where M() is Mertens function 1425 1425 = 3 × 52 × 19. It is a self-descriptive number in base 5. 1426 1426 = 2 × 23 × 31. It is a pentagonal number and the sum of the totient function for the first 68 integers. There are 1426 strict partitions of 42. 1427 1427 is a twin prime with 1429.A001359 Lesser of twin primes 1428 1428 = 22 × 3 × 7 × 17. There are 1428 complete ternary trees with 6 internal nodes or, equivalently, 18 edges.A001764 binomial(3*n,n)/(2*n+1) (enumerates ternary trees and also noncrossing trees) 1429 1429 is a twin prime with 1427. 1430 1430 = 2 × 5 × 11 × 13. It is a Catalan number.https://oeis.org/A000108 Sloane's A000108 : Catalan numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1431 1431 = 33 × 53. It is the 53rd triangular number and a hexagonal number. 1432 1432 = 23 × 179. It is a member of the Padovan sequence. 1433 1433 is a super-prime.A033548 Honaker primes: primes P(k) such that sum of digits of P(k) equals sum of digits of k 1435 1435 = 5 × 7 × 41. It is a vampire number. 1436 1436 = 22 × 359. It is the discriminant of a totally real cubic field.A006832 Discriminants of totally real cubic fields 1439 1439 is a Sophie Germain prime and a safe prime. 1440 1440 = 25 × 32 × 5. It is a highly totient number. 1441 1441 = 11 × 131. It is a star number. 1447 1447 is a super-prime number and a happy number. 1451 1451 is a Sophie Germain prime. 1452 1452 = 22 × 3 × 112. It is the first Zagreb index of the complete graph K12. 1453 1453 is a Sexy prime with 1459. 1458 1458 = 2 × 36. It is the maximum determinant of an 11 by 11 matrix of zeroes and onesHadamard J. Résolution d'une question relative aux déterminants Bulletin des Sciences Mathématiques 17 240–246 1893 and a 3-smooth number. 1458 is one of three numbers which, when its base 10 digits are added together, produces a sum which, when multiplied by its reversed self, yields the original number: 1 + 4 + 5 + 8 = 18 18 × 81 = 1458 The only other non-trivial numbers with this property are 81 and 1729, as well as the trivial solutions 1 and 0. It was proven by Masahiko Fujiwara.Fujiwara M. Introduction to Truly Beautiful Mathematics 100–101 2005 1459 1459 is a Sexy prime with 1453 and a Pierpont prime. It is the sum of nine consecutive primes: 1459 = 139 + 149 + 151 + 157 + 163 + 167 + 173 + 179 + 181. 1462 1462 = 2 × 17 × 43. Because 1462 = (35 - 1) × (35 + 8), it is the first Zagreb index of the wheel graph with 35 verticesA028569 n*(n + 9) 1467 1467 = 32 × 163. There are 1467 partitions of 39 with zero crank.A064410 Number of partitions of n with zero crank 1469 1469 = 13 × 113. It is an octahedral numberhttps://oeis.org/A005900 Sloane's A005900 : Octahedral numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 and a highly cototient number. 1470 1470 = 2 × 3 × 5 × 72. It is the sum of the totient function for the first 69 integers. 1471 1471 is a super-prime number and a centered heptagonal number. 1480 1480 = 23 × 5 × 37. It is the sum of the first 29 primes. 1481 1481 is a Sophie Germain prime. 1485 1485 = 33 × 5 × 11. It is the 54th triangular number. 1486 1486 = 2 × 743. There are 1486 strict solid partitions of 19.A323657 Number of strict solid partitions of n 1487 1487 is a safe prime. 1489 1489 is a prime number and a centered triangular number. 1490 1490 = 2 × 5 × 149. It is a tetranacci number.https://oeis.org/A000078 Sloane's A000078 : Tetranacci numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1491 1491 = 3 × 7 × 71. It is a nonogonal number. 1492 1492 = 22 × 373. It is the discriminant of a totally real cubic field. 1493 1493 is a Stern prime. 1494 1494 = 2 × 32 × 83. It is the sum of the totient function for the first 70 integers. 1496 1496 = 23 × 11 × 17. It is a square pyramidal number. 1499 1499 is a Sophie Germain prime and a super-prime. 1500 to 1599 1500 1500 = 22 × 3 × 53. It is the hypotenuse of three different Pythagorean triangles.A084647 Hypotenuses for which there exist exactly 3 distinct integer triangles 1501 1501 = 19 × 79. It is a centered pentagonal number. 1503 1503 = 32 × 167. Completing 12 revolutions of the Spiral of Theodorus requires 1503 triangles. 1510 1510 = 2 × 5 × 151. 1510 is an untouchable number. 1511 1511 is a Sophie Germain prime and a balanced prime. 1513 1513 = 17 × 89. It is a centered square number. 1520 1520 = 24 × 5 × 19. It is a pentagonal number. It forms a Ruth–Aaron pair with 1521 under the second definition. 1521 1521 = 32 × 132 = 392. It is a centered octagonal number. It forms a Ruth–Aaron pair with 1520 under the second definition. 1523 1523 is a super-prime, a safe prime, and a member of the Mian–Chowla sequence. 1525 1525 = 52 × 61. It is a heptagonal number. 1526 1526 = 2 × 7 × 109. There are 1526 conjugacy classes in the alternating group A27.A000702 number of conjugacy classes in the alternating group A_n 1529 1529 = 11 × 139. It is a composite de Polignac number. 1530 1530 = 2 × 32 × 5 × 17. It is a vampire number. 1531 1531 is a prime number and a centered decagonal number. 1532 1532 = 22 × 383. There are 1532 series-parallel networks with 9 unlabeled edges,A000084 Number of series-parallel networks with n unlabeled edges. Also called yoke-chains by Cayley and MacMahon 1535 1535 = 5 × 307. It is a Thabit number. 1537 1537 = 29 × 53. It is a Keith number. 1539 1539 = 34 × 19. A maximum of 1539 pieces can be obtained by cutting an annulus with 54 cuts. 1540 1540 = 22 × 5 × 7 × 11. It is the 55th triangular number, a hexagonal number, a decagonal number, and a tetrahedral number. 1541 1541 = 23 × 67. It is an octagonal number. 1549 1549 is a de Polignac prime.A065381 Primes not of the form p + 2^k 1557 1557 = 32 × 173. There are 1557 graphs with 8 nodes and 13 edges.A008406 Triangle T(n,k) read by rows, giving number of graphs with n nodes and k edges) 1559 1559 is a Sophie Germain prime. 1561 1561 = 7 × 223. It is a centered octahedral number. 1564 1564 = 22 × 17 × 23. It is the sum of the totient function for the first 71 integers. 1572 1572 = 22 × 3 × 131. It is a member of the Mian–Chowla sequence. 1573 1573 = 112 × 13. It is the discriminant of a totally real cubic field. 1583 1583 is a Sophie Germain prime. 1585 1585 = 5 × 307. It is a centered triangular number. 1588 1588 = 22 × 397. It is the sum of the totient function for the first 72 integers. 1589 1589 = 7 × 227. It is a composite de Polignac number. 1593 1593 = 33 × 59. It is the sum of the first 30 primes. 1594 1594 = 2 × 797. It is the minimal cost of a maximum height Huffman tree of size 17.A006327 Fibonacci(n) - 3. Number of total preorders 1596 1596 = 22 × 3 × 7 × 19. It is the 56th triangular number. 1597 1597 is a super-prime, a Fibonacci prime,https://oeis.org/A000045 Sloane's A000045 : Fibonacci numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 a Markov prime, and an emirp. 1600 to 1699 1601 1601 is a Sophie Germain prime and a Proth prime. 1607, 1609, and 1613 1607, 1609, and 1613 form a prime triple. 1617 1617 = 3 × 72 × 11. It is a pentagonal number. 1618 1618 = 2 × 809. It is a centered heptagonal number. 1619 1619 is a safe prime. 1621 1621 is a super-prime. 1624 1624 = 23 × 7 × 29. There are 1624 squares in the Aztec diamond of order 28.A046092 4 times triangular numbers 1625 1625 = 53 × 13. It is a centered square number. 1626 1626 = 2 × 3 × 271. It is a centered pentagonal number. 1633 1633 = 23 × 71. It is a star number. 1634 1634 = 2 × 19 × 43. It is the smallest four-digit Narcissistic number in base 10. 1637 1637 is a prime island: it is the smallest prime whose adjacent primes are exactly 30 apart.A046931 Prime islands: least prime whose adjacent primes are exactly 2n apart 1638 1638 = 2 × 32 × 7 × 13. It is a harmonic divisor number.https://oeis.org/A001599 Sloane's A001599 : Harmonic or Ore numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1639 1639 = 11 × 149. It is a nonagonal number. 1646 1646 = 2 × 823. There are 1646 graphs with 8 nodes and 14 edges. 1649 1649 = 17 × 97. It is a highly cototient number and a Leyland numberA076980 Leyland numbers: 3, together with numbers expressible as n^k + k^n nontrivially, i.e., n,k > 1 (to avoid n = (n-1)^1 + 1^(n-1)) using 4 and 5: 1649 = 45 + 54. 1651 1651 = 13 × 127. It is a heptagonal number. 1653 1653 = 3 × 19 × 29. It is the 57th triangular number and a hexagonal number. 1657 1657 is a cuban prime.https://oeis.org/A002407 Sloane's A002407 : Cuban primes The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1660 1660 = 22 × 5 × 83. It is the sum of the totient function for the first 73 integers. 1665 1665 = 32 × 5 × 37. It is a centered tetrahedral number. 1669 1669 is a super-prime. It is the smallest prime with a gap of exactly 24 to the next prime.A000230 smallest prime p such that there is a gap of exactly 2n between p and next prime 1679 1679 = 23 × 73. It is a highly cototient number. 1680 1680 = 24 × 3 × 5 × 7. It is the 17th highly composite number. 1681 1681 = 412 = 402 + 40 + 41. It is the smallest number yielded by the formula n2 + n + 41, where n is a natural number, that is not a prime. It is also a centered octagonal number. 1682 and 1683 1682 and 1683 form a Ruth–Aaron pair under the first definition. 1684 1684 = 22 × 421. It is a centered triangular number. 1691 1691 = 19 × 89. It is a strobogrammatic number.A000787 Strobogrammatic numbers: the same upside down 1695 1695 = 3 × 5 × 113. It is the magic constant of n × n normal magic square and the n-queens problem for n = 15. 1696 1696 = 25 × 53. It is the sum of the totient function for the first 74 integers. 1700 to 1799 1705 1705 = 5 × 11 × 13. It is a tribonacci number.https://oeis.org/A000073 Sloane's A000073 : Tribonacci numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1710 1710 = 2 × 32 × 5 × 19. A maximum of 1710 pieces can be obtained by cutting an annulus 57 times. 1711 1711 = 29 × 59. It is the 58th triangular number and a centered decagonal number. 1717 1717 = 17 × 101. It is a pentagonal number. 1719 1719 = 32 × 131. it is a composite de Polignac number. 1720 1720 = 23 × 5 × 43. It is the sum of the first 31 primes. 1721 1721 is a twin prime with 1723.A028387 n + (n+1)^2 1722 1722 (number) 1723 1723 is a twin prime with 1721. It is also a super-prime. 1728 1728 (number) 1729 1729 (number) 1733 1733 is a Sophie Germain prime. It is palindromic in bases 3, 18, and 19. 1736 1736 = 23 × 7 × 31. It is the sum of the totient function for the first 75 integers. 1740 1740 = 22 × 3 × 5 × 29. There are 1740 squares in the Aztec diamond of order 29. 1741 1741 is a super-prime and a centered square number. 1747 1747 is a balanced prime. 1750 1750 = 2 × 53 × 7. It is the hypotenuse of three different Pythagorean triangles with integer side lengths. 1753 1753 is a balanced prime. 1756 1756 = 22 × 439. It is a centered pentagonal number. 1757 1757 = 7 × 251. Completing 13 revolutions around the Spiral of Theodorus requires 1757 triangles. 1759 1759 is a de Polignac prime. 1765 1765 = 5 × 353. There are 1765 planar partitions of 15.A001523 Number of stacks, or planar partitions of n; also weakly unimodal compositions of n 1769 1769 = 29 × 61. A maximum of 1769 pieces can be obtained by cutting an annulus with 58 times. 1770 1770 = 2 × 3 × 59. It is the 59th triangular number and a hexagonal number. 1771 1771 = 7 × 11 × 23. It is a tetrahedral number. 1772 1772 = 22 × 443. It is a centered heptagonal number and the sum of the totient function for the first 76 integers. 1776 1776 = 24 × 3 × 37. It is the 24th square star number.A045944 Rhombic matchstick numbers: n*(3*n+2) A total of 1776 pieces could be seen in a 7 × 7 × 7 × 7 Rubik's Tesseract. 1782 1782 = 2 × 34 × 11. It is a heptagonal number. 1783 1783 is a de Polignac prime. 1785 1785 = 3 × 5 × 7 × 17. It is a square pyramidal number. 1786 1786 = 2 × 19 × 47. It is a centered triangular number. 1787 1787 is a super-prime. It is the sum of eleven consecutive primes: 1787 = 137 + 139 + 149 + 151 + 157 + 163 + 167 + 173 + 179 + 181 + 191. 1792 1792 = 28 × 7. It is a Granville number. 1794 1794 = 2 × 3 × 13 × 23. It is a nonagonal number. 1800 to 1899 1801 1801 is a cuban prime. It is the sum of five consecutive primes (349 + 353 + 359 + 367 + 373) and nine consecutive primes 179 + 181 + 191 + 193 + 197 + 199 + 211 + 223 + 227). 1806 1806 = 2 × 3 × 301. It is a pronic number, a primary pseudoperfect number,https://oeis.org/A054377 Sloane's A054377 : Primary pseudoperfect numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 and a Schröder number.A006318 Large Schröder numbers 2016-05-22 It is the only number n such that the denominator of the nth Bernoulli number is n.Kellner, Bernard C.; 'The equation denom(Bn) = n has only one solution' 1807 1807 = 13 × 139. It is the fifth term of Sylvester's sequence.https://oeis.org/A000058 Sloane's A000058 : Sylvester's sequence The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1811 1811 is a Sophie Germain prime. 1820 1820 = 22 × 5 × 7 × 13. It is a pentagonal number and a pentatope number. 1821 1821 = 3 × 607. It is a member of the Mian–Chowla sequence. 1823 1823 is a super-prime and a safe prime. 1825 1825 = 52 × 73. It is an octagonal number. 1827 1827 = 32 × 7 × 29. It is a vampire number. 1828 1828 = 22 × 457. It is a meandric number as well as an open meandric number. 1829 1829 = 31 × 59. composite de Polignac number. 1830 1830 = 2 × 3 × 5 × 61. It is the 60th triangular number. 1831 1831 is the smallest prime number with a gap of exactly 16 to the next prime, 1847.A000230 smallest prime p such that there is a gap of exactly 2n between p and next prime, or -1 if no such prime exists 1834 1834 = 2 × 7 × 131. It is an octahedral number. 1837 1837 = 11 × 167. It is a star number. 1841 1841 = 7 × 263. It is the solution to the postage stamp problem with 3 denominations and 29 stamps.A001208 solution to the postage stamp problem with 3 denominations and n stamps 1847 1847 is a super-prime. 1859 1859 = 11 × 132. It is a composite de Polignac number. 1861 1861 is a prime number and a centered square number. 1862 and 1863 1862 and 1863 form a Ruth–Aaron pair under the second definition. 1867 1867 is a prime de Polignac number. 1870 1870 = 2 × 5 × 11 × 17. It is a decagonal number. 1871, 1873, 1877, and 1879 1871, 1873, 1877, and 1879 form a prime quadruple.A007530 Prime quadruples: numbers k such that k, k+2, k+6, k+8 are all prime There are 1873 Narayana's cows and calves after 21 years. 1880 1880 = 23 × 5 × 47. It is the 10th element of the self convolution of Lucas numbers.A004799 Self convolution of Lucas numbers 1882 1882 = 2 × 941. There are 1882 linearly separable Boolean functions in 4 variables.A000609 Number of threshold functions of n or fewer variables 1889 1889 is a Sophie Germain prime and a highly cototient number. 1891 1891 = 31 × 61. It is the 61st triangular number, a centered triangular number a hexagonal number, a centered pentagonal number, and the sum of 5 consecutive primes: 1891 = 367 + 373 + 379 + 383 + 389. 1892 1892 = 22 × 11 × 43. It is a pronic number. 1896 1896 = 23 × 3 × 79. It is a member of the Mian-Chowla sequence. 1897 1897 = 7 × 271. It is a member of the Padovan sequence. 1900 to 1999 1900 1900 is the third largest number whose roman numeral is a palindrome.A078715 Palindromic Roman numerals 1901 1901 is a Sophie Germain prime and a centered decagonal number. 1905 1905 = 3 × 5 × 127. It is a Fermat pseudoprime.A001567 Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers 1907 1907 is a safe prime and a balanced prime. 1909 1909 = 23 × 83. It is a hyperperfect number.https://oeis.org/A034897 Sloane's A034897 : Hyperperfect numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-06-12 1913 1913 is a super-prime. 1918 1918 = 2 × 7 × 137. It is a heptagonal number. 1926 1926 = 2 × 32 × 107. It is a pentagonal number. 1931 1931 is a Sophie Germain prime. 1933 1933 is a prime number and a centered heptagonal number. 1951 1951 is a cuban prime. 1953 1953 = 32 × 7 × 31. It is the 62nd triangular number. 1956 1956 = 22 × 3 × 163. It is a nonagonal number. 1969 1969 = 11 × 179. It is the only number less than four million for which a "mod-ification" of the standard Ackermann Function does not stabilizeA Mod-n Ackermann Function, or What's So Special About 1969? https://archive.org/details/sim_american-mathematical-monthly_1993-02_100_2/page/180 Jon Froemke Jerrold W. Grossman amp The American Mathematical Monthly 100 2 Feb 1993 180–183 Mathematical Association of America 2323780 10.2307/2323780 1973 1973 is a Sophie Germain prime and a Leonardo prime. 1976 1976 = 23 × 13 × 19. It is an octagonal number. 1980 1980 = 22 × 32 × 5 × 11. It is a pronic numberA002378 Oblong (or promic, pronic, or heteromecic) numbers and a highly abundant number, and it also has a greater aliquot sum than any smaller number.A034090 Numbers k whose sum of proper divisors exceeds that of all smaller numbers 1985 1985 = 5 × 397. It is a centered square number. 1987 1987 is the first number of a sexy prime triplet (1987, 1993, 1999). It is a lucky number and therefore also a lucky prime.A031157 Numbers that are both lucky and prime 2026-08-22 1990 1990 = 2 × 5 × 199. It is a Stella octangula number. 1993 1993 forms a prime triplet with 1987 and 1999. 1999 1999 is a prime number that forms a prime triplet with 1987 and 1993. It is also a centered triangular number. There are 1999 regular forms in a myriagram. Prime numbers There are 135 prime numbers between 1000 and 2000:A038823 Number of primes between n*1000 and (n+1)*1000Stein William A. William A. Stein The Riemann Hypothesis and The Birch and Swinnerton-Dyer Conjecture https://wstein.org/talks/2017-02-10-wing-rh_and_bsd/ wstein.org 10 February 2017 6 February 2021 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997, 1999 References Mathematics 30em 10 Category:Integers