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 A366041 #8 Sep 27 2023 10:06:03
%S A366041 1,1,2,5,15,48,160,549,1930,6919,25200,92976,346757,1305140,4951216,
%T A366041 18912245,72675114,280761670,1089800270,4248149795,16623209911,
%U A366041 65273370720,257115465600,1015719256200,4023178881540,15974388769653,63570826294760
%N A366041 Expansion of (1/x) * Series_Reversion( x*(1-x)*(1-x^4) ).
%F A366041 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} binomial(n+k,n) * binomial(2*n-4*k,n).
%o A366041 (PARI) a(n) = sum(k=0, n\4, binomial(n+k, n)*binomial(2*n-4*k, n))/(n+1);
%Y A366041 Cf. A006013, A063020, A063030, A366042.
%Y A366041 Cf. A366023.
%K A366041 nonn
%O A366041 0,3
%A A366041 _Seiichi Manyama_, Sep 26 2023