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 A369525 #19 Jan 27 2024 10:31:38
%S A369525 1,1,1,1,2,5,11,21,40,84,190,429,944,2067,4613,10505,24092,55182,
%T A369525 126444,291232,675144,1571934,3667774,8573365,20090498,47214710,
%U A369525 111237828,262587843,620911708,1470701157,3489548683,8293157045,19738018740,47039738570,112247416400
%N A369525 Expansion of (1/x) * Series_Reversion( x / (1+x+x^4/(1+x)) ).
%H A369525 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369525 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} binomial(n+1,k) * binomial(n-2*k+1,n-4*k).
%o A369525 (PARI) my(N=40, x='x+O('x^N)); Vec(serreverse(x/(1+x+x^4/(1+x)))/x)
%o A369525 (PARI) a(n) = sum(k=0, n\4, binomial(n+1, k)*binomial(n-2*k+1, n-4*k))/(n+1);
%Y A369525 Cf. A367317.
%K A369525 nonn
%O A369525 0,5
%A A369525 _Seiichi Manyama_, Jan 26 2024