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 A365252 #9 Aug 29 2023 08:52:55
%S A365252 1,1,1,1,1,2,5,11,21,36,60,106,205,418,851,1685,3257,6264,12210,24276,
%T A365252 48920,98873,199118,399472,801361,1613713,3266772,6640770,13526547,
%U A365252 27564804,56183565,114612879,234187293,479442918,983236998,2018936664,4149222198
%N A365252 G.f. satisfies A(x) = 1 + x*A(x)*(1 + x^4*A(x)^2).
%F A365252 a(n) = Sum_{k=0..floor(n/5)} binomial(n-4*k,k) * binomial(n-2*k+1,n-4*k)/(n-2*k+1).
%o A365252 (PARI) a(n) = sum(k=0, n\5, binomial(n-4*k, k)*binomial(n-2*k+1, n-4*k)/(n-2*k+1));
%Y A365252 Cf. A000108, A071879, A364552.
%K A365252 nonn
%O A365252 0,6
%A A365252 _Seiichi Manyama_, Aug 29 2023