20673

Appears in sequences

• Numbers k such that k | 11^k + 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k + 2^k + 1^k.at n=36A057292
• McKay-Thompson series of class 30d for Monster.at n=37A058625
• a(n) is the number of labeled connected planar graphs with n edges.at n=5A291842
• Number of labeled connected graphs with n edges (the vertices are {1,2,...,k} for some k).at n=6A322137
• L.g.f.: -log( Sum_{n=-oo..+oo} (-p)^n * (p*x)^(n^2) ) = Sum_{n>=1} a(n) * x^n/n, where p = sqrt(2).at n=13A337948
• Expansion of g.f. A(x) satisfying A(x)^3 = A( x^3/(1 - 3*x)^3 ).at n=8A361763