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 A377706 #23 Dec 13 2024 09:40:35
%S A377706 1,1,0,3,-6,28,-105,444,-1897,8338,-37305,169471,-779537,3623500,
%T A377706 -16993990,80316081,-382136133,1828896726,-8798796709,42528048930,
%U A377706 -206413678447,1005623593109,-4916026689088,24106987842416,-118551374861525,584526569727010,-2888995759466360
%N A377706 G.f. A(x) satisfies A(x) = 1 + x/A(x)^3 * (1 - A(x) + A(x)^4).
%F A377706 a(n) = (1/n) * Sum_{k=0..n} (-1)^k * binomial(n,k) * binomial(n-4*k,n-k-1) for n > 0.
%o A377706 (PARI) a(n) = if(n==0, 1, sum(k=0, n, (-1)^k*binomial(n, k)*binomial(n-4*k, n-k-1))/n);
%Y A377706 Cf. A317133, A364759, A377458, A378958, A378920.
%Y A377706 Cf. A371890.
%K A377706 sign
%O A377706 0,4
%A A377706 _Seiichi Manyama_, Dec 12 2024