A382367 Expansion of 1/( 1 - Sum_{k>=0} x^(3^k) / (1 - x^(3^k)) ).

1, 1, 2, 5, 10, 21, 46, 97, 206, 442, 940, 2002, 4272, 9103, 19400, 41360, 88156, 187901, 400534, 853747, 1819782, 3878965, 8268160, 17623888, 37566072, 80073580, 170680002, 363811370, 775478548, 1652963605, 3523358532, 7510180375, 16008251264, 34122231512

Offset: 0

Author

Seiichi Manyama, Mar 22 2025

Keywords

• nonn

Crossrefs

Cf. A327736, A382372, A382373, A382378.

Cf. A382368, A382369.

Cf. A051064.

Formula

a(0) = 1; a(n) = Sum_{k=1..n} A051064(k) * a(n-k).

G.f.: 1/(1 - Sum_{i>=1, j>=0} x^(i*3^j)).

G.f. A(x) satisfies A(x) = 1/( 1/A(x^3) - x/(1-x) ).