A377691 E.g.f. satisfies A(x) = (1 - x * log(1 - x) * A(x))^3.

1, 0, 6, 9, 312, 1530, 47952, 468720, 15273696, 238738752, 8404102080, 185234979600, 7145001364608, 204957002147040, 8705298805015680, 307822476591957600, 14400927608439260160, 604208707715034777600, 31065769175985079142400, 1504405685073556864627200

Offset: 0

Author

Seiichi Manyama, Nov 04 2024

Keywords

• nonn

Crossrefs

Cf. A052830, A377438.

Cf. A371141.

Programs

PARI

a(n) = 3*n!*sum(k=0, n\2, (3*k+2)!*abs(stirling(n-k, k, 1))/((n-k)!*(2*k+3)!));

Formula

E.g.f.: B(x)^3, where B(x) is the e.g.f. of A371141.

a(n) = 3 * n! * Sum_{k=0..floor(n/2)} (3*k+2)! * |Stirling1(n-k,k)|/( (n-k)! * (2*k+3)! ).