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

Author

Seiichi Manyama, Dec 20 2023

Keywords

• nonn
• easy

Crossrefs

Cf. A092148, A368294.

Programs

PARI

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

Formula

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