A367715 G.f. A(x) satisfies A(x) = 1 / ((1 - x) * (1 - x * (1 + x + x^2 + x^3) * A(x^4))).

1, 2, 4, 8, 16, 33, 68, 140, 288, 594, 1225, 2526, 5208, 10740, 22148, 45673, 94184, 194224, 400524, 825950, 1703249, 3512395, 7243168, 14936668, 30801992, 63519044, 130987274, 270118452, 557031032, 1148694482, 2368807011, 4884890405, 10073490200

Offset

0,2

Links

Table of n, a(n) for n=0..32.

Formula

a(n) = 1 + Sum_{k=0..n-1} a(floor(k/4)) * a(n-1-k).

Prog

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

Crossrefs

Cf. A367713, A367714.

Cf. A367657, A367692.

Sequence in context: A324406 A182442 A098588 * A126683 A005821 A177794

Adjacent sequences: A367712 A367713 A367714 * A367716 A367717 A367718

Keyword

nonn

Author

Seiichi Manyama, Nov 28 2023

Status

approved