A390036 a(n) = Sum_{k=0..floor(3*n/8)} binomial(k+2,3*n-8*k).

1, 0, 0, 3, 0, 0, 6, 0, 1, 10, 0, 6, 15, 0, 21, 21, 1, 56, 28, 9, 126, 36, 45, 252, 46, 165, 462, 67, 495, 792, 144, 1287, 1288, 442, 3003, 2017, 1456, 6435, 3123, 4473, 12871, 5048, 12496, 24328, 9248, 31960, 43929, 20196, 75736, 76722, 50388, 168152, 131955

Offset

0,4

Links

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

Index entries for linear recurrences with constant coefficients, signature (0,0,3,0,0,-3,0,1,1).

Formula

G.f.: 1 / ((1-x^3)^3 - x^8).

a(n) = 3*a(n-3) - 3*a(n-6) + a(n-8) + a(n-9).

Prog

(PARI) my(N=60, x='x+O('x^N)); Vec(1/((1-x^3)^3-x^8))

Crossrefs

Cf. A390034.

Sequence in context: A390037 A062688 A067181 * A321429 A145225 A392316

Adjacent sequences: A390033 A390034 A390035 * A390037 A390038 A390039

Keyword

nonn,easy

Author

Seiichi Manyama, Jan 14 2026

Status

approved