A360089 a(n) = Sum_{k=0..n} (-1)^k * binomial(5*k,n-k).

1, -1, -4, -1, 21, 29, -80, -244, 153, 1473, 836, -6920, -12220, 23209, 91213, -21511, -510680, -457965, 2210520, 4921941, -6271749, -33288595, -3876765, 173223185, 214943855, -682969376, -1912499375, 1498348275, 11882164650, 5332839025, -57402248250, -92821609874

Offset

0,3

Links

Table of n, a(n) for n=0..31.

Index entries for linear recurrences with constant coefficients, signature (-1,-5,-10,-10,-5,-1).

Formula

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

G.f.: 1/(1 + x*(1+x)^5).

Prog

(PARI) a(n) = sum(k=0, n, (-1)^k*binomial(5*k, n-k));
(PARI) my(N=40, x='x+O('x^N)); Vec(1/(1+x*(1+x)^5))

Crossrefs

Cf. A077979, A360087, A360088.

Cf. A360090.

Sequence in context: A202550 A364760 A142472 * A299445 A135049 A113384

Adjacent sequences: A360086 A360087 A360088 * A360090 A360091 A360092

Keyword

sign,easy

Author

Seiichi Manyama, Jan 25 2023

Status

approved