A373518 Expansion of e.g.f. exp(x/(1 - x^3)^(2/3)).

1, 1, 1, 1, 17, 81, 241, 3361, 32481, 183457, 2534561, 36903681, 325995121, 4808334961, 90981786897, 1126128625441, 18354227120321, 415821040873281, 6714588707173441, 122710186163310337, 3174234862391072721, 63597591858999638161, 1308604168710672673841

Offset

0,5

Links

Table of n, a(n) for n=0..22.

Formula

a(n) = n! * Sum_{k=0..floor(n/3)} binomial(2*n/3-k-1,k)/(n-3*k)!.

a(n) == 1 mod 16.

Prog

(PARI) a(n) = n!*sum(k=0, n\3, binomial(2*n/3-k-1, k)/(n-3*k)!);

Crossrefs

Cf. A293493, A373517.

Cf. A373523.

Sequence in context: A044204 A044585 A373523 * A347501 A197397 A354012

Adjacent sequences: A373515 A373516 A373517 * A373519 A373520 A373521

Keyword

nonn

Author

Seiichi Manyama, Jun 08 2024

Status

approved