A368295 Expansion of e.g.f. exp(-x) / (1 - x*exp(3*x)).

1, 0, 7, 47, 549, 7859, 134743, 2694537, 61595593, 1584039383, 45262146411, 1422647401493, 48780718512397, 1812012517295811, 72486789793754911, 3106846273709042609, 142039582571511632529, 6899664100487740573871, 354870658975988082859219

Offset

0,3

Links

Table of n, a(n) for n=0..18.

Formula

a(n) = n! * Sum_{k=0..n} (3*(n-k)-1)^k / k!.

Prog

(PARI) a(n) = n!*sum(k=0, n, (3*(n-k)-1)^k/k!);

Crossrefs

Cf. A092148, A368294.

Sequence in context: A288722 A006873 A228695 * A268063 A015097 A341213

Adjacent sequences: A368292 A368293 A368294 * A368296 A368297 A368298

Keyword

nonn,easy

Author

Seiichi Manyama, Dec 20 2023

Status

approved