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 A368937 #12 Jan 10 2024 07:59:23
%S A368937 1,2,7,30,143,727,3861,21165,118845,680064,3951291,23247874,138229486,
%T A368937 829292780,5013767772,30516496017,186837457296,1149894814718,
%U A368937 7110026033305,44146396259805,275139524189497,1720647439298395,10793938343564655,67905034046934225
%N A368937 Expansion of (1/x) * Series_Reversion( x * (1-x) * (1-x+x^5) ).
%F A368937 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/5)} (-1)^k * binomial(n+k,k) * binomial(3*n-4*k+1,n-5*k).
%o A368937 (PARI) a(n) = sum(k=0, n\5, (-1)^k*binomial(n+k, k)*binomial(3*n-4*k+1, n-5*k))/(n+1);
%o A368937 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x*(1-x)*(1-x+x^5))/x)
%Y A368937 Cf. A129442, A368935, A368936.
%Y A368937 Cf. A366046, A368933.
%K A368937 nonn
%O A368937 0,2
%A A368937 _Seiichi Manyama_, Jan 10 2024