A377340 E.g.f. satisfies A(x) = ( 1 + (exp(x*A(x)) - 1)/A(x) )^3.

1, 3, 9, 54, 531, 6498, 101925, 1920222, 42251391, 1067567850, 30411486441, 965077330374, 33764590958571, 1291198144146498, 53587639922183757, 2398901329112787630, 115225387686206361495, 5911249981088653607898, 322592377196349009882513

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Formula

E.g.f.: B(x)^3, where B(x) is the e.g.f. of A377348.

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

Prog

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

Crossrefs

Cf. A377326, A377339.

Cf. A377348.

Sequence in context: A025226 A001194 A032179 * A233189 A175117 A245117

Adjacent sequences: A377337 A377338 A377339 * A377341 A377342 A377343

Keyword

nonn

Author

Seiichi Manyama, Oct 26 2024

Status

approved