A113331 a(n) = Sum_{k=0..n} 6^k*A111146(n,k).

1, 6, 72, 900, 11520, 149904, 1976400, 26363232, 355648320, 4854292416, 67114780416, 941774874624, 13451571452160, 196362144456192, 2945496714485760, 45717104468689920, 740282299231703040

Offset: 0

Author

Philippe Deléham and Paul D. Hanna, Oct 26 2005

Keywords

• nonn

Examples

			A(x) = (1 + 6*x + 72*x^2 + 900*x^3 + 11520*x^4 + 149904*x^5 +..)
= 1/(1 - 6/5!*x*(5! + 6!*x + 7!*x^2 + 8!*x^3 + 9!*x^4 +..) ).
		

Crossrefs

Cf. A111146, A113326, A113327 (y=2), A113328 (y=3), A113329 (y=4), A113330 (y=5).

Programs

PARI

{a(n)=local(y=6,x=X+X*O(X^n)); polcoeff(1/(1 - y/(y-1)!*x*sum(k=0,n,(y-1+k)!*x^k)),n,X)}

Formula

G.f.: A(x) = 1/(1 - (1/20)*x*Sum_{k>=0} (k+5)!*x^k ).