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 A301834 #7 Nov 05 2021 05:48:34
%S A301834 1,1,6,77,1710,59882,3091200,222190789,21227659638,2599346122814,
%T A301834 396581942797668,73721984076543090,16398099489074850108,
%U A301834 4299479561194904805396,1312142733349302902243508,461104766297721671082897333,184846637953491751729984324518,83842823980101547405726058204534
%N A301834 G.f. A(x) satisfies: A(x) = 1/(1 - x*A(x)/(1 - 4*x*A(x)/(1 - 9*x*A(x)/(1 - 16*x*A(x)/(1 - ... - k^2*x*A(x)/(1 - ...)))))), a continued fraction.
%F A301834 a(n) = [x^n] (Sum_{k>=0} A000364(k)*x^k)^(n+1)/(n + 1).
%F A301834 a(n) ~ 2^(4*n + 3) * n^(2*n + 1/2) / (exp(2*n) * Pi^(2*n + 1/2)). - _Vaclav Kotesovec_, Nov 05 2021
%e A301834 G.f. A(x) = 1 + x + 6*x^2 + 77*x^3 + 1710*x^4 + 59882*x^5 + 3091200*x^6 + 222190789*x^7 + 21227659638*x^8 + ...
%t A301834 Table[SeriesCoefficient[(1 + Sum[Abs[EulerE[2*k]]*x^k, {k, 1, n}])^(n+1)/(n+1), {x, 0, n}], {n, 0, 20}] (* _Vaclav Kotesovec_, Nov 05 2021 *)
%Y A301834 Cf. A000364, A301363.
%K A301834 nonn
%O A301834 0,3
%A A301834 _Ilya Gutkovskiy_, Mar 27 2018