A365693 G.f. satisfies A(x) = 1 + x*A(x) / (1 - x^2*A(x)^5).

1, 1, 1, 2, 8, 30, 103, 368, 1407, 5531, 21905, 87689, 355929, 1461022, 6046160, 25194331, 105661615, 445692621, 1889454880, 8045796200, 34398989998, 147606568810, 635481458969, 2744158752772, 11882687400375, 51584960268914, 224465280616995, 978851595046223

Offset

0,4

Links

Table of n, a(n) for n=0..27.

Formula

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

Prog

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

Crossrefs

Cf. A101785, A365244, A365692.

Cf. A365691.

Sequence in context: A299415 A364078 A230701 * A168605 A127865 A199923

Adjacent sequences: A365690 A365691 A365692 * A365694 A365695 A365696

Keyword

nonn

Author

Seiichi Manyama, Sep 16 2023

Status

approved