A371585 G.f. satisfies A(x) = ( 1 + x*A(x)^(5/2) / (1 - x)^2 )^2.

1, 2, 15, 130, 1263, 13210, 145254, 1655566, 19385489, 231803136, 2818714210, 34749228048, 433317651224, 5455934825956, 69267925684377, 885756704750960, 11397912218979769, 147483397060856046, 1917785255491649284, 25047838828467708506, 328444729414573179950

Offset

0,2

Links

Seiichi Manyama, Table of n, a(n) for n = 0..873

Formula

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

Prog

(PARI) a(n, r=2, s=2, t=5, u=0) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(n+(s-1)*k-1, n-k)/(t*k+u*(n-k)+r));

Crossrefs

Cf. A371580, A371583.

Sequence in context: A242091 A132182 A365151 * A140306 A374975 A143924

Adjacent sequences: A371582 A371583 A371584 * A371586 A371587 A371588

Keyword

nonn

Author

Seiichi Manyama, Mar 28 2024

Status

approved