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 A366082 #13 Sep 30 2023 09:18:54
%S A366082 1,2,6,21,79,308,1219,4826,18857,71574,257553,837114,2140496,1379550,
%T A366082 -35589730,-370646635,-2719034151,-17429175486,-103771133876,
%U A366082 -588804389677,-3225403649859,-17180039158530,-89342552789741,-454604059204324,-2265246385921936
%N A366082 Expansion of (1/x) * Series_Reversion( x*(1-x)^3/(1-x-x^2) ).
%H A366082 Seiichi Manyama, <a href="/A366082/b366082.txt">Table of n, a(n) for n = 0..1000</a>
%F A366082 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} (-1)^k * binomial(n+1,k) * binomial(3*n-k+1,n-2*k).
%o A366082 (PARI) a(n) = sum(k=0, n\2, (-1)^k*binomial(n+1, k)*binomial(3*n-k+1, n-2*k))/(n+1);
%Y A366082 Cf. A007440, A108623, A366081, A366083.
%Y A366082 Cf. A366049.
%K A366082 sign
%O A366082 0,2
%A A366082 _Seiichi Manyama_, Sep 28 2023