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 A366366 #9 Oct 08 2023 10:50:17
%S A366366 1,2,-6,58,-574,6402,-75878,939290,-12000318,157050178,-2094657926,
%T A366366 28368411194,-389079656446,5393118559938,-75431624084838,
%U A366366 1063251390845338,-15088643098754942,215396586102923138,-3091050571516120582,44566089825496186170
%N A366366 G.f. satisfies A(x) = (1 + x/A(x)^4)/(1 - x).
%F A366366 a(n) = (-1)^(n-1) * Sum_{k=0..n} binomial(5*k-1,k) * binomial(4*k-1,n-k)/(5*k-1).
%o A366366 (PARI) a(n) = (-1)^(n-1)*sum(k=0, n, binomial(5*k-1, k)*binomial(4*k-1, n-k)/(5*k-1));
%Y A366366 Cf. A346626, A349310, A349311, A349312, A349313, A349314, A366363, A366364, A366365.
%Y A366366 Cf. A366359.
%K A366366 sign
%O A366366 0,2
%A A366366 _Seiichi Manyama_, Oct 08 2023