A368292 Expansion of e.g.f. exp(x) / (1 - x*exp(3*x)).

1, 2, 11, 97, 1109, 15821, 271255, 5425967, 124032137, 3189663433, 91141189931, 2864686414547, 98226339773677, 3648723468367277, 145961603607355775, 6256040115149251591, 286015221831125756945, 13893373399551594686609, 714578347872583574806099

Offset: 0

Author

Seiichi Manyama, Dec 19 2023

Keywords

• nonn
• easy

Crossrefs

Cf. A336948, A368293.

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!.