A030037 a(n+1) = Sum_{k=0..floor(2*n/5)} a(k) * a(n-k).
1, 1, 1, 1, 2, 3, 6, 11, 20, 40, 77, 160, 319, 636, 1332, 2721, 5799, 12068, 25109, 53943, 113682, 245931, 523896, 1115239, 2425858, 5208339, 11388934, 24630843, 53194684, 116764483, 253764437, 559289434, 1221970242, 2666776056, 5889628123, 12910470041, 28608337855
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..1000
Programs
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PARI
lista(nn) = {my(v=vector(nn+2, i, 1)); for(n=2, nn, v[n+2]=sum(k=1, 1+(2*n)\5, v[k]*v[n+2-k])); v; } \\ Jinyuan Wang, Mar 18 2020
Extensions
More terms from Jinyuan Wang, Mar 18 2020