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 A369511 #10 Jan 25 2024 07:50:43
%S A369511 1,4,26,206,1815,17082,168159,1710234,17828973,189504744,2045971440,
%T A369511 22374997320,247344411792,2759394009008,31027178033064,
%U A369511 351270123392892,4000793799046578,45809545263096832,527010005799822844,6088666065809281348,70612995488695876634
%N A369511 Expansion of (1/x) * Series_Reversion( x * ((1-x)^2-x^3)^2 ).
%H A369511 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A369511 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} binomial(2*n+k+1,k) * binomial(5*n-k+3,n-3*k).
%o A369511 (PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x*((1-x)^2-x^3)^2)/x)
%o A369511 (PARI) a(n) = sum(k=0, n\3, binomial(2*n+k+1, k)*binomial(5*n-k+3, n-3*k))/(n+1);
%Y A369511 Cf. A368962, A369514.
%Y A369511 Cf. A369214.
%K A369511 nonn
%O A369511 0,2
%A A369511 _Seiichi Manyama_, Jan 25 2024