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 A365697 #9 Sep 16 2023 10:40:50
%S A365697 1,0,0,0,1,1,1,1,4,8,13,19,38,79,153,273,509,999,1979,3818,7331,14279,
%T A365697 28189,55599,109275,215165,426093,846638,1683215,3348212,6673679,
%U A365697 13333171,26679522,53437369,107151335,215154204,432586412,870678377,1754094266
%N A365697 G.f. satisfies A(x) = 1 + x^4*A(x)^3 / (1 - x*A(x)).
%F A365697 a(n) = Sum_{k=0..floor(n/4)} binomial(n-3*k-1,n-4*k) * binomial(n-k+1,k) / (n-k+1).
%o A365697 (PARI) a(n) = sum(k=0, n\4, binomial(n-3*k-1, n-4*k)*binomial(n-k+1, k)/(n-k+1));
%Y A365697 Cf. A023427, A215341, A215342, A357308, A365696.
%Y A365697 Cf. A365245.
%K A365697 nonn
%O A365697 0,9
%A A365697 _Seiichi Manyama_, Sep 16 2023