A368294 Expansion of e.g.f. exp(-x) / (1 - x*exp(2*x)).

1, 0, 5, 26, 257, 3004, 42277, 694182, 13027233, 275027480, 6451456421, 166468606930, 4685926374241, 142896198878484, 4692784128725253, 165121528707826334, 6197343209916830657, 247136182723119609520, 10434957969449887989445, 465078400154112693602826

Offset: 0

Author

Seiichi Manyama, Dec 20 2023

Keywords

• nonn
• easy

Crossrefs

Cf. A092148, A368295.

Programs

PARI

a(n) = n!*sum(k=0, n, (2*(n-k)-1)^k/k!);

Formula

a(n) = n! * Sum_{k=0..n} (2*(n-k)-1)^k / k!.