A357926 a(n) = Sum_{k=0..floor(n/4)} Stirling2(n - 3*k,n - 4*k).

1, 1, 1, 1, 1, 2, 4, 7, 11, 17, 29, 54, 102, 187, 337, 619, 1179, 2298, 4488, 8733, 17085, 33931, 68407, 139030, 283474, 580477, 1198195, 2496661, 5241757, 11061986, 23453024, 50008919, 107338755, 231825945, 503294589, 1097731342, 2405837254, 5300147291

Offset

0,6

Links

Table of n, a(n) for n=0..37.

Formula

G.f.: Sum_{k>=0} x^k/Product_{j=1..k} (1 - j * x^4).

Prog

(PARI) a(n) = sum(k=0, n\4, stirling(n-3*k, n-4*k, 2));
(PARI) my(N=40, x='x+O('x^N)); Vec(sum(k=0, N, x^k/prod(j=1, k, 1-j*x^4)))

Crossrefs

Cf. A024428, A357925.

Cf. A357904.

Sequence in context: A152398 A023427 A216116 * A129929 A360891 A073738

Adjacent sequences: A357923 A357924 A357925 * A357927 A357928 A357929

Keyword

nonn

Author

Seiichi Manyama, Oct 20 2022

Status

approved