This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A030037 #11 Oct 15 2021 14:59:26
%S A030037 1,1,1,1,2,3,6,11,20,40,77,160,319,636,1332,2721,5799,12068,25109,
%T A030037 53943,113682,245931,523896,1115239,2425858,5208339,11388934,24630843,
%U A030037 53194684,116764483,253764437,559289434,1221970242,2666776056,5889628123,12910470041,28608337855
%N A030037 a(n+1) = Sum_{k=0..floor(2*n/5)} a(k) * a(n-k).
%H A030037 Seiichi Manyama, <a href="/A030037/b030037.txt">Table of n, a(n) for n = 0..1000</a>
%o A030037 (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
%Y A030037 Cf. A000992, A030036, A030038, A030039.
%K A030037 nonn
%O A030037 0,5
%A A030037 _N. J. A. Sloane_
%E A030037 More terms from _Jinyuan Wang_, Mar 18 2020