A391323 - OEIS

A391323

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

1, 1, 3, 19, 126, 883, 6501, 49624, 389219, 3118063, 25405808, 209894543, 1754221320, 14805022999, 125999049473, 1080121504069, 9318158935631, 80837824742241, 704782805163339, 6171975753494542, 54265986220547723, 478850411498305225, 4239332681969820266

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

OFFSET

0,3

LINKS

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

FORMULA

a(n) = Sum_{k=0..floor(n/2)} (-1)^k * (2*k+1) * binomial(4*n-6*k+1,n-2*k)/(4*n-6*k+1).

PROG

(PARI) a(n) = sum(k=0, n\2, (-1)^k*(2*k+1)*binomial(4*n-6*k+1, n-2*k)/(4*n-6*k+1));

CROSSREFS

Cf. A002293, A391097.

Sequence in context: A074572 A157455 A027308 * A295371 A156069 A058860