A376731 - OEIS

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A376731

Expansion of (1 - x^4 - x^5)/((1 - x^4 - x^5)^2 - 4*x^9).

1, 0, 0, 0, 1, 1, 0, 0, 1, 6, 1, 0, 1, 15, 15, 1, 1, 28, 70, 28, 2, 45, 210, 210, 46, 67, 495, 924, 496, 157, 1002, 3003, 3004, 1121, 1911, 8009, 12871, 8161, 4880, 18684, 43760, 43948, 23409, 41820, 126124, 184988, 133285, 113373, 324616, 647112, 657273, 454366

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

OFFSET

0,10

LINKS

Table of n, a(n) for n=0..51.

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

FORMULA

a(n) = 2*a(n-4) + 2*a(n-5) - a(n-8) + 2*a(n-9) - a(n-10).

a(n) = Sum_{k=0..floor(n/4)} binomial(2*k,2*n-8*k).

PROG

(PARI) my(N=60, x='x+O('x^N)); Vec((1-x^4-x^5)/((1-x^4-x^5)^2-4*x^9))

(PARI) a(n) = sum(k=0, n\4, binomial(2*k, 2*n-8*k));