48360

Appears in sequences

• Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-1,0,1}.at n=23A079985
• Numbers that can be expressed as the difference of the squares of primes in exactly six distinct ways.at n=27A092002
• a(n) = number of Egyptian fractions 1 = 1/x_1 + ... + 1/x_k (for any k), 0<x_1<...<x_k<=n.at n=54A092670
• G.f. A(x) satisfies: 4^n - 1 = Sum_{k=0..n} [x^k] A(x)^n and also satisfies: (4+z)^n - (1+z)^n + z^n = Sum_{k=0..n} [x^k](A(x)+z*x)^n for all z, where [x^k] A(x)^n denotes the coefficient of x^k in A(x)^n.at n=12A100228
• a(n) = 121*n^2 - 2*n.at n=19A157040
• a(n) = 1728*n - 24.at n=27A157287
• Numbers n such that sigma(n) = 14*phi(n) (where sigma=A000203, phi=A000010).at n=6A171259
• Number of simple graphs with n unlabeled vertices with the degree of each vertex a prime number.at n=9A182096
• Triangle read by rows: coefficients eta(n,k) arising from the study of completely transitive graphs on n nodes.at n=17A259970
• Number of regular tetrahedra in an n-node-per-edge tetrahedral grid.at n=25A269747
• Non-primitive balanced numbers: balanced numbers of the form m*n where m, n > 1 are both balanced.at n=45A291566
• Number of n X 2 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 0, 1 or 3 neighboring 1s.at n=9A296572
• Subtract 1 from each term of A004094 (the powers of 2 written backwards).at n=14A341718
• a(n) = Sum_{d|n} sigma_d(d)^(n/d).at n=5A359053
• Number of conjugacy classes in the group GL(4,Z_n).at n=14A364770
• Table read by rows: row n is the unique primitive Pythagorean triple (a,b,c) such that (a-b+c)/2 = A002378(n) and its long leg and hypotenuse are consecutive natural numbers.at n=34A385022
• Let p = A002145(n) be the n-th prime == 3 (mod 4); a(n) is the multiplicative order of 2+-i modulo p in Gaussian integers.at n=33A385165