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 A366085 #13 Sep 29 2023 09:27:50
%S A366085 1,3,15,90,596,4199,30869,234091,1817720,14380288,115492518,939163680,
%T A366085 7717237661,63979604459,534498370665,4495171005567,38026764744348,
%U A366085 323358790454352,2762410748226232,23697028402783512,204044822552956179,1762917281476448944
%N A366085 Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1-x-x^3) ).
%H A366085 Seiichi Manyama, <a href="/A366085/b366085.txt">Table of n, a(n) for n = 0..1000</a>
%F A366085 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} (-1)^k * binomial(n+1,k) * binomial(4*n-2*k+2,n-3*k).
%o A366085 (PARI) a(n) = sum(k=0, n\3, (-1)^k*binomial(n+1, k)*binomial(4*n-2*k+2, n-3*k))/(n+1);
%Y A366085 Cf. A049133, A243157, A366084.
%Y A366085 Cf. A366053.
%K A366085 nonn
%O A366085 0,2
%A A366085 _Seiichi Manyama_, Sep 28 2023