A377689 E.g.f. satisfies A(x) = (1 + x * (exp(x*A(x)) - 1))^3.

1, 0, 6, 9, 300, 1995, 48438, 720111, 17965944, 422161011, 12234150930, 380328463383, 13151800946628, 497667965729259, 20320277028840558, 899482574279597535, 42525760204244934768, 2153233176660303831267, 115738033009558749725610, 6600044862098481204272487

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Formula

E.g.f.: B(x)^3, where B(x) is the e.g.f. of A377690.

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

Prog

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

Crossrefs

Cf. A371115, A377688.

Cf. A377690.

Sequence in context: A367881 A367879 A377720 * A377691 A377686 A264375

Adjacent sequences: A377686 A377687 A377688 * A377690 A377691 A377692

Keyword

nonn

Author

Seiichi Manyama, Nov 04 2024

Status

approved