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 A369631 #9 Jan 28 2024 09:19:42
%S A369631 1,1,2,5,15,49,168,594,2149,7920,29640,112359,430564,1665197,6491280,
%T A369631 25478886,100611695,399421439,1593221090,6382176160,25664184349,
%U A369631 103560846454,419215870860,1701907025715,6927658961599,28268225980197,115608889788304
%N A369631 Expansion of (1/x) * Series_Reversion( x * (1/(1+x^4) - x) ).
%H A369631 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369631 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} binomial(2*n-4*k+1,k) * binomial(2*n-4*k,n-4*k).
%o A369631 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x*(1/(1+x^4)-x))/x)
%o A369631 (PARI) a(n) = sum(k=0, n\4, binomial(2*n-4*k+1, k)*binomial(2*n-4*k, n-4*k))/(n+1);
%Y A369631 Cf. A007863, A199874, A369630.
%Y A369631 Cf. A227035.
%K A369631 nonn
%O A369631 0,3
%A A369631 _Seiichi Manyama_, Jan 28 2024