A030041 a(n+1) = Sum_{k=0..sqrt(n)} a(k) * a(n-k).

1, 1, 2, 3, 5, 12, 23, 45, 92, 183, 434, 936, 2012, 4365, 9551, 20748, 45065, 108070, 245109, 553308, 1253492, 2846553, 6482338, 14721344, 33423804, 75916943, 187505118, 441004027, 1032009219, 2419549459, 5676752449, 13331861333, 31398821908, 73794930935

Offset

0,3

Links

Table of n, a(n) for n=0..33.

Prog

(PARI) lista(nn) = {my(v=vector(nn+2, i, 1)); for(n=0, nn, v[n+2]=sum(k=1, 1+sqrt(n), v[k]*v[n+2-k])); v; } \\ Jinyuan Wang, Mar 18 2020

Crossrefs

Cf. A000992.

Sequence in context: A124370 A003428 A191626 * A331811 A284910 A233231

Adjacent sequences: A030038 A030039 A030040 * A030042 A030043 A030044

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Jinyuan Wang, Mar 18 2020

Status

approved