A394270 - OEIS

A394270

a(n) = binomial(5*n+2,n).

1, 7, 66, 680, 7315, 80730, 906192, 10295472, 118030185, 1362649145, 15820024220, 184509266760, 2160153123141, 25371763481680, 298824321028320, 3527930788646880, 41738112995067045, 494705855605882455, 5873182941643167150, 69829208430263393040, 831331027085222426070

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Paolo Xausa, Table of n, a(n) for n = 0..921

FORMULA

G.f.: g^3/(5-4*g) where g = 1+x*g^5 is the g.f. of A002294.

a(n) ~ 5^(5*n+5/2)/(2^(8*n+11/2)*sqrt(Pi*n)). - Amiram Eldar, May 21 2026

MATHEMATICA

A394270[n_] := Binomial[5*n + 2, n]; Array[A394270, 25, 0] (* Paolo Xausa, May 20 2026 *)

PROG

(PARI) a(n) = binomial(5*n+2, n);