A366268 G.f. A(x) satisfies A(x) = 1 + x + x*A(x)^5.

1, 2, 10, 90, 930, 10530, 126282, 1576410, 20268930, 266591490, 3569991370, 48509238810, 667157894050, 9269347395490, 129908752970890, 1834347364277530, 26071297610067970, 372683901080814850, 5354668071305293450, 77286026066830771930

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Formula

a(n) = Sum_{k=0..n} binomial(4*k+1,n-k) * binomial(5*k,k)/(4*k+1).

a(n) = A366273(n) + A366273(n-1).

G.f.: A(x) = 1/B(-x) where B(x) is the g.f. of A366366.

Prog

(PARI) a(n) = sum(k=0, n, binomial(4*k+1, n-k)*binomial(5*k, k)/(4*k+1));

Crossrefs

Cf. A025227, A366266, A366267.

Cf. A366273, A366366.

Sequence in context: A055779 A363425 A338050 * A198434 A326089 A277403

Adjacent sequences: A366265 A366266 A366267 * A366269 A366270 A366271

Keyword

nonn

Author

Seiichi Manyama, Oct 06 2023

Status

approved