80955

Appears in sequences

• Coefficient of x^4 in expansion of (1+x+x^2)^n.at n=34A005712
• a(n) = trinomial(2*n, 4) = (1/6)*n*(2*n - 1)*(2*n^2 + 7*n - 3).at n=18A302710
• Irregular triangle read by rows: T(n,k) = number of homeomorphically irreducible connected labeled graphs with n vertices and k edges, n >= 1, 0 <= k <= n*(n-1)/2.at n=54A331438
• Numbers k such that k + 1 divides 3^k + 1.at n=11A370578