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 A366086 #8 Sep 28 2023 12:07:53
%S A366086 1,-1,1,-1,0,4,-14,34,-65,89,-29,-331,1464,-4148,9010,-14366,9761,
%T A366086 38895,-215015,674423,-1594973,2829973,-2732465,-4812567,36116257,
%U A366086 -124617681,316617081,-611942761,735416371,488457845,-6451021289,24658985649,-66990721867,139346533259
%N A366086 Expansion of (1/x) * Series_Reversion( x/(1-x-x^4) ).
%F A366086 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/4)} (-1)^(n-k) * binomial(n+1,k) * binomial(n-k+1,n-4*k).
%o A366086 (PARI) a(n) = sum(k=0, n\4, (-1)^(n-k)*binomial(n+1, k)*binomial(n-k+1, n-4*k))/(n+1);
%Y A366086 Cf. A366087, A366088, A366089, A366090.
%Y A366086 Cf. A366051, A366057.
%K A366086 sign
%O A366086 0,6
%A A366086 _Seiichi Manyama_, Sep 28 2023