A377453 E.g.f. satisfies A(x) = 1/(1 - A(x) * (exp(x) - 1))^3.

1, 3, 33, 639, 18177, 687663, 32585793, 1858893039, 124128928257, 9502575055983, 820716875385153, 78959656742857839, 8375163183606235137, 971063889443489669103, 122194096152956362997313, 16586054767142612489229039, 2415658529914018225123490817, 375779208568915395913102663023

Offset: 0

Author

Seiichi Manyama, Oct 28 2024

Keywords

• nonn

Crossrefs

Cf. A052895, A377452, A377454.

Cf. A377450.

Programs

PARI

a(n) = 3*sum(k=0, n, (4*k+2)!/(3*k+3)!*stirling(n, k, 2));

Formula

E.g.f.: B(x)^3, where B(x) is the e.g.f. of A377450.

a(n) = 3 * Sum_{k=0..n} (4*k+2)!/(3*k+3)! * Stirling2(n,k).