A392588 - OEIS

A392588

Expansion of 1 / ((1-x)^4 - x^4)^2.

1, 8, 36, 120, 332, 816, 1872, 4160, 9168, 20224, 44608, 97920, 213184, 460032, 985344, 2099200, 4455680, 9431040, 19911680, 41932800, 88083456, 184578048, 385929216, 805355520, 1677709312, 3489529856, 7247511552, 15032156160, 31138562048, 64425099264, 133145100288

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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 (8,-28,56,-68,48,-16).

FORMULA

a(n) = Sum_{k=0..floor(n/4)} (k+1) * binomial(n+7,n-4*k).

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 68*a(n-4) + 48*a(n-5) - 16*a(n-6).

PROG

(PARI) my(N=40, x='x+O('x^N)); Vec(1/((1-x)^4-x^4)^2)

CROSSREFS