42471

Appears in sequences

• Number of alternating sign n X n matrices symmetric with respect to both diagonals.at n=10A005162
• Expansion of Product_{m>=1} (1-m*q^m)^27.at n=7A022687
• Concatenations C1 and C2 and C3 are all prime (see the comment lines).at n=9A034818
• Number of intersections of at least four edges in a cube of n X n X n smaller cubes.at n=33A126562
• The Wiener index of the meta-polyphenyl chain with n hexagons (see the Dou et al. and the Deng references).at n=12A216110
• Values of x such that x^2 + y^2 = 41^n with x and y coprime and 0 < x < y.at n=5A230743
• Number of collinear point triples on a centered hexagonal grid of size n.at n=9A241222
• a(n) = Product_{k=0..n} (3*k)!/(n+k)!.at n=5A266091
• a(n) = H(n-1, n, n+1) where H(a, b, c) = (a + b + c)*(a + b - c)*(b + c - a)*(c + a - b) is Heron's polynomial.at n=11A339488