A376650 a(n) = Sum_{k=0..floor(n/4)} binomial(floor(k/3),n-4*k).

1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 2, 1, 0, 1, 2, 1, 0, 1, 2, 1, 0, 1, 3, 3, 1, 1, 3, 3, 1, 1, 3, 3, 1, 1, 4, 6, 4, 2, 4, 6, 4, 2, 4, 6, 4, 2, 5, 10, 10, 6, 6, 10, 10, 6, 6, 10, 10, 6, 7, 15, 20, 16, 12, 16, 20, 16, 12, 16, 20, 16, 13, 22, 35, 36

Offset

0,26

Links

Table of n, a(n) for n=0..88.

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

Formula

G.f.: (1-x^12)/((1-x^4) * (1-x^12-x^13)) = (1+x^4+x^8)/(1-x^12-x^13).

a(n) = a(n-12) + a(n-13).

Prog

(PARI) a(n) = sum(k=0, n\4, binomial(k\3, n-4*k));
(PARI) my(N=90, x='x+O('x^N)); Vec((1+x^4+x^8)/(1-x^12-x^13))

Crossrefs

Cf. A079398, A376649.

Sequence in context: A286320 A330888 A194525 * A330466 A282938 A065368

Adjacent sequences: A376647 A376648 A376649 * A376651 A376652 A376653

Keyword

nonn,easy

Author

Seiichi Manyama, Oct 01 2024

Status

approved