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 A369506 #8 Jan 25 2024 07:50:08
%S A369506 1,6,53,548,6192,74074,922142,11822082,155024190,2069570934,
%T A369506 28033435791,384329462490,5322745393480,74357950874850,
%U A369506 1046564375245893,14826433687124098,211251475010201934,3025331234242178508,43523061969049245589,628692982662691174722
%N A369506 Expansion of (1/x) * Series_Reversion( x / ((1+x)^3+x^2)^2 ).
%H A369506 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369506 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} binomial(2*n+2,k) * binomial(6*n-3*k+6,n-2*k).
%o A369506 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/((1+x)^3+x^2)^2)/x)
%o A369506 (PARI) a(n) = sum(k=0, n\2, binomial(2*n+2, k)*binomial(6*n-3*k+6, n-2*k))/(n+1);
%Y A369506 Cf. A143927, A369503.
%K A369506 nonn
%O A369506 0,2
%A A369506 _Seiichi Manyama_, Jan 25 2024