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 A366025 #22 Sep 26 2023 14:01:52
%S A366025 1,1,2,5,14,43,139,465,1595,5577,19804,71228,258946,950030,3513050,
%T A366025 13079920,48993149,184490361,698020080,2652192675,10115878915,
%U A366025 38717526745,148655862210,572412768275,2209969761924,8553073927858,33176952295730,128960722306128
%N A366025 Expansion of (1/x) * Series_Reversion( x*(1-x)/(1+x^5) ).
%F A366025 G.f. satisfies A(x) = 1 + x*A(x)^2*(1 + x^4*A(x)^3).
%F A366025 a(n) = Sum_{k=0..floor(n/5)} binomial(n-4*k,k) * binomial(2*n-5*k+1,n-4*k)/(2*n-5*k+1) = (1/(n+1)) * Sum_{k=0..floor(n/5)} binomial(n+1,k) * binomial(2*n-5*k,n-5*k).
%t A366025 CoefficientList[InverseSeries[Series[x(1-x)/(1+x^5),{x,0,28}],x]/x,x] (* _Stefano Spezia_, Sep 26 2023 *)
%o A366025 (PARI) a(n) = sum(k=0, n\5, binomial(n-4*k, k)*binomial(2*n-5*k+1, n-4*k)/(2*n-5*k+1));
%o A366025 (PARI) Vec(serreverse(x*(1-x)/(1+x^5)+O(x^30))/x) \\ _Michel Marcus_, Sep 26 2023
%Y A366025 Cf. A006318, A052709, A071969, A365268.
%Y A366025 Cf. A365760, A366024.
%K A366025 nonn
%O A366025 0,3
%A A366025 _Seiichi Manyama_, Sep 26 2023