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 A366051 #9 Sep 27 2023 10:06:10
%S A366051 1,-1,1,0,-3,9,-16,13,29,-157,391,-562,-32,3002,-10373,20747,-18083,
%T A366051 -47941,271117,-712216,1066699,122131,-6464446,22907125,-46951992,
%U A366051 40883304,120187926,-679375906,1809757015,-2731745887,-468147579,17768126376,-63256877763
%N A366051 Expansion of (1/x) * Series_Reversion( x/(1-x+x^3) ).
%F A366051 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} (-1)^(n-k) * binomial(n+1,k) * binomial(n-k+1,n-3*k).
%o A366051 (PARI) a(n) = sum(k=0, n\3, (-1)^(n-k)*binomial(n+1, k)*binomial(n-k+1, n-3*k))/(n+1);
%Y A366051 Cf. A049128, A114997, A366052, A366053.
%Y A366051 Cf. A071879.
%K A366051 sign
%O A366051 0,5
%A A366051 _Seiichi Manyama_, Sep 27 2023