A357025 E.g.f. satisfies log(A(x)) = (exp(x * A(x)) - 1)^3.
1, 0, 0, 6, 36, 150, 3060, 62286, 867636, 15591750, 419764500, 10834588446, 277719263316, 8580282719190, 297021183388020, 10459810717672686, 393932179466738676, 16351788886638987750, 717798906181149294420, 32905220431196072057406
Offset: 0
Keywords
Programs
-
PARI
a(n) = sum(k=0, n\3, (3*k)!*(n+1)^(k-1)*stirling(n, 3*k, 2)/k!);
Formula
a(n) = Sum_{k=0..floor(n/3)} (3*k)! * (n+1)^(k-1) * Stirling2(n,3*k)/k!.