A391324 - OEIS

A391324

Expansion of g/(1 + x^3*g^2), where g = 1+x*g^4 is the g.f. of A002293.

1, 1, 4, 21, 137, 954, 6994, 53213, 416373, 3329569, 27090831, 223562019, 1866713744, 15742216041, 133887231109, 1147097367757, 9891135180443, 85771988717376, 747520002860926, 6544049472151928, 57520178203664694, 507429329176282329, 4491253149879401475

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OFFSET

0,3

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..1000

FORMULA

a(n) = Sum_{k=0..floor(n/3)} (-1)^k * (2*k+1) * binomial(4*n-10*k+1,n-3*k)/(4*n-10*k+1).

PROG

(PARI) a(n) = sum(k=0, n\3, (-1)^k*(2*k+1)*binomial(4*n-10*k+1, n-3*k)/(4*n-10*k+1));

CROSSREFS

Cf. A002293, A391098.

Sequence in context: A288268 A052852 A265952 * A369784 A121124 A389372