A364340 G.f. satisfies A(x) = (1 + x*A(x)) * (1 + x*A(x)^6).

1, 2, 15, 179, 2502, 38262, 619991, 10459410, 181771289, 3231782239, 58505593456, 1074766446526, 19984671314164, 375414901633692, 7113886504446443, 135820770971898805, 2610186429457347486, 50452256583633573513, 980187901557594671335, 19130197594133100828170, 374894511736219913097375

Offset: 0

Author

Seiichi Manyama, Jul 19 2023

Keywords

• nonn

Crossrefs

Cf. A239109, A364333, A364339.

Cf. A007863, A198953, A215623, A215624.

Programs

PARI

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

Formula

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