A030032 a(n+1) = Sum_{k=0..floor(n/3)} a(k) * a(n-k).

1, 1, 1, 1, 2, 3, 5, 10, 18, 33, 66, 127, 244, 506, 1009, 2018, 4229, 8631, 17631, 37265, 77349, 160433, 342807, 720334, 1513791, 3254445, 6902283, 14634519, 31602375, 67522598, 144182089, 312851626, 672411931, 1444776938, 3145883976, 6794243911, 14667444523

Offset

0,5

Links

Seiichi Manyama, Table of n, a(n) for n = 0..1000

Prog

(PARI) lista(nn) = {my(v=vector(nn+2, i, 1)); for(n=3, nn, v[n+2]=sum(k=1, 1+n\3, v[k]*v[n+2-k])); v; } \\ Jinyuan Wang, Mar 18 2020

Crossrefs

Cf. A000992, A030034, A030036.

Sequence in context: A199594 A081172 A318301 * A002661 A216959 A065053

Adjacent sequences: A030029 A030030 A030031 * A030033 A030034 A030035

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Jinyuan Wang, Mar 18 2020

Status

approved