A366452 G.f. A(x) satisfies A(x) = 1 + x + x*A(x)^(5/2).

1, 2, 5, 20, 90, 440, 2266, 12110, 66525, 373320, 2130865, 12332512, 72202860, 426861830, 2544727475, 15280236800, 92333523153, 561054410200, 3426075429740, 21013974400920, 129403499560500, 799733464576880, 4958649842375975, 30837325310579350

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Formula

G.f.: A(x) = 1/B(-x) where B(x) is the g.f. of A366404.

a(n) = Sum_{k=0..n} binomial(3*k/2+1,n-k) * binomial(5*k/2,k) / (3*k/2+1).

G.f.: A(x) = B(x)^2 where B(x) is the g.f. of A259757. - Seiichi Manyama, Apr 04 2024

Prog

(PARI) a(n) = sum(k=0, n, binomial(3*k/2+1, n-k)*binomial(5*k/2, k)/(3*k/2+1));

Crossrefs

Cf. A112478, A364393, A364407, A364408, A364409, A366266, A366267, A366268, A366453, A366454, A366455, A366456.

Cf. A259757, A366404.

Sequence in context: A258830 A002484 A280102 * A277686 A115082 A020105

Adjacent sequences: A366449 A366450 A366451 * A366453 A366454 A366455

Keyword

nonn

Author

Seiichi Manyama, Oct 10 2023

Status

approved