A385648 G.f. A(x) satisfies A(x) = 1/( 1 - x*(A(x) + A(2*x))^2 ).

1, 4, 64, 1872, 91328, 7563648, 1115422976, 306988895488, 162926170881024, 169827391985854464, 350891899856754294784, 1443597302250006622052352, 11851990053153536620868173824, 194396568906445310993071164686336, 6373487768490075927307409156798611456

Offset

0,2

Links

Table of n, a(n) for n=0..14.

Formula

a(0) = 1; a(n) = Sum_{i, j, k>=0 and i+j+k=n-1} (2^j+1) * (2^k+1) * a(i) * a(j) * a(k).

Crossrefs

Cf. A385617, A385649.

Cf. A171192, A385650.

Sequence in context: A050636 A098698 A301583 * A181398 A326274 A081559

Adjacent sequences: A385645 A385646 A385647 * A385649 A385650 A385651

Keyword

nonn

Author

Seiichi Manyama, Jul 06 2025

Status

approved