A360897 G.f. satisfies A(x) = 1 + x * A(x * (1 - x^3)).

1, 1, 1, 1, 1, 0, -2, -5, -9, -8, 7, 48, 120, 161, -18, -798, -2486, -4088, -692, 19840, 71159, 130467, 31737, -688014, -2644266, -5066453, -866551, 31217375, 121457519, 231494879, -10834753, -1756652362, -6638239650, -12044755426, 5372265122, 117373545212

Offset

0,7

Links

Table of n, a(n) for n=0..35.

Formula

a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/4)} (-1)^k * binomial(n-1-3*k,k) * a(n-1-3*k).

Prog

(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=0, (i-1)\4, (-1)^j*binomial(i-1-3*j, j)*v[i-3*j])); v;

Crossrefs

Cf. A360894, A360896.

Cf. A360886.

Sequence in context: A020852 A053477 A104956 * A020820 A111290 A129140

Adjacent sequences: A360894 A360895 A360896 * A360898 A360899 A360900

Keyword

sign

Author

Seiichi Manyama, Feb 25 2023

Status

approved