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 A366023 #16 Sep 26 2023 12:48:35
%S A366023 1,1,2,5,13,36,104,309,940,2915,9184,29328,94747,309180,1017824,
%T A366023 3376693,11279274,37906330,128085630,434913555,1483226921,5078436800,
%U A366023 17450556480,60159492600,208013078910,721205983737,2506764055592,8733076109732,30489081691750
%N A366023 Expansion of (1/x) * Series_Reversion( x*(1-x)*(1+x^4) ).
%F A366023 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} (-1)^k * binomial(n+k,n) * binomial(2*n-4*k,n).
%t A366023 CoefficientList[InverseSeries[Series[x(1-x)(1+x^4),{x,0,29}],x]/x,x] (* _Stefano Spezia_, Sep 26 2023 *)
%o A366023 (PARI) a(n) = sum(k=0, n\4, (-1)^k*binomial(n+k, n)*binomial(2*n-4*k, n))/(n+1);
%Y A366023 Cf. A063019, A063026, A366024.
%K A366023 nonn
%O A366023 0,3
%A A366023 _Seiichi Manyama_, Sep 26 2023