A392553 - OEIS

A392553

Expansion of 1 / ((1-x)^2 - x^5)^2.

1, 4, 10, 20, 35, 58, 96, 162, 277, 472, 793, 1312, 2147, 3494, 5674, 9202, 14893, 24032, 38651, 61976, 99136, 158274, 252282, 401518, 638078, 1012526, 1604489, 2539302, 4014105, 6338710, 9999569, 15759890, 24816299, 39043884, 61379259, 96419020, 151354198

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OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1,2,-4,2,0,0,-1).

FORMULA

G.f.: B(x)^2, where B(x) is the g.f. of A392540.

a(n) = Sum_{k=0..floor(n/5)} (k+1) * binomial(n-3*k+3,n-5*k).

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + 2*a(n-5) - 4*a(n-6) + 2*a(n-7) - a(n-10).

PROG

(PARI) my(N=40, x='x+O('x^N)); Vec(1/((1-x)^2-x^5)^2)