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 A364827 #17 Aug 09 2023 16:57:19 %S A364827 1,2,26,478,10254,240122,5950530,153417542,4072868742,110585691634, %T A364827 3056671795946,85722961493742,2433127206219582,69763483031049066, %U A364827 2017643094336224914,58789801741123032918,1724199860717303739062,50858327392484088101346 %N A364827 G.f. satisfies A(x) = 1 - x*A(x)^5 * (1 - 3*A(x)). %H A364827 Seiichi Manyama, <a href="/A364827/b364827.txt">Table of n, a(n) for n = 0..666</a> %F A364827 a(n) = (-1)^n * Sum_{k=0..n} (-3)^k * binomial(n,k) * binomial(5*n+k+1,n) / (5*n+k+1). %F A364827 a(n) = (1/n) * Sum_{k=0..n-1} 2^(n-k) * binomial(n,k) * binomial(6*n-k,n-1-k) for n > 0. %F A364827 a(n) = (1/n) * Sum_{k=1..n} 2^k * 3^(n-k) * binomial(n,k) * binomial(5*n,k-1) for n > 0. %o A364827 (PARI) a(n) = (-1)^n*sum(k=0, n, (-3)^k*binomial(n, k)*binomial(5*n+k+1, n)/(5*n+k+1)); %Y A364827 Cf. A025192, A107841, A235347, A364825, A364826. %Y A364827 Cf. A243668, A363006. %K A364827 nonn %O A364827 0,2 %A A364827 _Seiichi Manyama_, Aug 09 2023