147 (number)

147 1, 3, 7, 21, 49, 147 147 (one hundred [and] forty-seven) is the natural number following 146 and preceding 148. In mathematics 147 is the fourth centered icosahedral number. These are a class of figurate numbers that represent points in the shape of a regular icosahedron or alternatively points in the shape of a cuboctahedron, and are magic numbers for the face-centered cubic lattice.A005902 Centered icosahedral (or cuboctahedral) numbers, also crystal ball sequence for f.c.c. lattice Separately, it is also a magic number for the diamond cubic.A007904 Crystal ball sequence for diamond It is also the fourth Apéry number following 19, whereA005258 Apéry numbers with 147 the composite index of the nineteenth triangle number, 190.A002808 The composite numbers: numbers n of the form x*y for x > 1 and y > 1. 2023-12-29 A000217 Triangular number: a(n) is the binomial(n+1,2) equivalent to n*(n+1)/2 that is 0 + 1 + 2 + ... + n. 2023-12-29 There are 147 different ways of representing one as a sum of unit fractions with five terms, allowing repeated fractions,A002966 Egyptian fractions: number of solutions of 1 1/x_1 + ... + 1/x_n where 0 < x_1 ≤ ... ≤ x_n and 147 different self-avoiding polygonal chains of length six using horizontal and vertical segments of the integer lattice.A037245 Number of unrooted self-avoiding walks of n steps on square lattice See also 147 (disambiguation) References 1 Category:Integers