A368293 Expansion of e.g.f. exp(2*x) / (1 - x*exp(3*x)).

1, 3, 16, 137, 1572, 22457, 384934, 7699449, 176004376, 4526214641, 129331581954, 4065059876033, 139385578253524, 5177627842411065, 207123084913936174, 8877473910719477033, 405862594146337680816, 19715036609777115714401, 1014004150296746677804666

Offset: 0

Author

Seiichi Manyama, Dec 19 2023

Keywords

• nonn
• easy

Crossrefs

Cf. A336948, A368292.

Programs

PARI

a(n) = n!*sum(k=0, n, (3*(n-k)+2)^k/k!);

Formula

a(n) = n! * Sum_{k=0..n} (3*(n-k)+2)^k / k!.