A030039 a(n+1) = Sum_{k=0..floor(4*n/5)} a(k) * a(n-k).

1, 1, 1, 2, 4, 9, 21, 42, 97, 233, 570, 1414, 3319, 8208, 20595, 52370, 133955, 328261, 833652, 2136155, 5519116, 14341917, 36069212, 93074465, 241613666, 630653714, 1652472131, 4215072482, 10985970447, 28756470626, 75580683613, 199201407564, 513021407584

Offset

0,4

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=1, nn, v[n+2]=sum(k=1, 1+(4*n)\5, v[k]*v[n+2-k])); v; } \\ Jinyuan Wang, Mar 18 2020

Crossrefs

Cf. A000992, A030036, A030037, A030038.

Sequence in context: A079060 A225173 A346737 * A018105 A035056 A332800

Adjacent sequences: A030036 A030037 A030038 * A030040 A030041 A030042

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Jinyuan Wang, Mar 18 2020

Status

approved