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 A351818 #9 May 31 2022 02:39:43 %S A351818 1,1,6,31,211,1841,18547,210664,2682657,37807531,581985596,9696297528, %T A351818 173702897000,3327063115248,67790086866271,1462900566163696, %U A351818 33310115601839624,797687851718024035,20032231443590167914,526189230537615409571,14423255501358439152231 %N A351818 G.f. A(x) satisfies: A(x) = 1 + x * A(x/(1 - x)^5) / (1 - x)^5. %H A351818 Seiichi Manyama, <a href="/A351818/b351818.txt">Table of n, a(n) for n = 0..452</a> %F A351818 a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n+4*k+3,n-k-1) * a(k). %t A351818 nmax = 20; A[_] = 0; Do[A[x_] = 1 + x A[x/(1 - x)^5]/(1 - x)^5 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] %t A351818 a[0] = 1; a[n_] := a[n] = Sum[Binomial[n + 4 k + 3, n - k - 1] a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 20}] %Y A351818 Cf. A000110, A045500, A125274, A351815, A351816, A351817. %K A351818 nonn %O A351818 0,3 %A A351818 _Ilya Gutkovskiy_, Feb 20 2022