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 A364758 #22 Dec 11 2024 08:45:34 %S A364758 1,1,3,14,76,450,2818,18352,123028,843345,5884227,41650479,298352365, %T A364758 2158751879,15754446893,115830820439,857147952469,6379136387303, %U A364758 47715901304501,358529599468636,2704884469806606,20481615947325089,155605509972859999,1185779099027494848 %N A364758 G.f. A(x) satisfies A(x) = 1 + x*A(x)^4 / (1 + x*A(x)). %H A364758 Seiichi Manyama, <a href="/A364758/b364758.txt">Table of n, a(n) for n = 0..1000</a> %F A364758 a(n) = (1/n) * Sum_{k=0..n-1} (-1)^k * binomial(n,k) * binomial(4*n-3*k,n-1-k) for n > 0. %F A364758 From _Seiichi Manyama_, Dec 11 2024: (Start) %F A364758 G.f. A(x) satisfies A(x)^3 = 1 + x*A(x) + x*A(x)^5 + x*A(x)^6. %F A364758 G.f. A(x) satisfies A(x) = 1/(1 - x*A(x)^3/(1 + x*A(x))). %F A364758 If g.f. satisfies A(x) = ( 1 + x*A(x)^(t/r) * (1 + x*A(x)^(u/r))^s )^r, then a(n) = r * Sum_{k=0..n} binomial(t*k+u*(n-k)+r,k) * binomial(s*k,n-k)/(t*k+u*(n-k)+r). (End) %o A364758 (PARI) a(n) = if(n==0, 1, sum(k=0, n-1, (-1)^k*binomial(n, k)*binomial(4*n-3*k, n-1-k))/n); %o A364758 (PARI) a(n, r=1, s=-1, t=4, u=1) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(s*k, n-k)/(t*k+u*(n-k)+r)); \\ _Seiichi Manyama_, Dec 11 2024 %Y A364758 Cf. A090192, A106228, A364759, A378919. %Y A364758 Cf. A001764, A219537, A364865, A365224. %Y A364758 Cf. A300048, A364747, A378889. %K A364758 nonn %O A364758 0,3 %A A364758 _Seiichi Manyama_, Aug 05 2023