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 A303568 #14 Apr 27 2018 06:28:38
%S A303568 1,2,2,32,62,1764,3916,173376,393446,25166076,56406348,4958003840,
%T A303568 10882283500,1264942740680,2721161685880,405344510959872,
%U A303568 857860989902854,159511701001085164,333452808033317004,75711389658286217024,156849644184430434436
%N A303568 a(n) = [x^n] ((Sum_{k=0..n} (k+3)!*x^k)/(Sum_{k=0..n} (k+3)!*(-x)^k))^(1/4).
%H A303568 Seiichi Manyama, <a href="/A303568/b303568.txt">Table of n, a(n) for n = 0..448</a>
%o A303568 (PARI) N=66; x='x+O('x^N); Vec((sum(k=0, N, (k+3)!*x^k)/sum(k=0, N, (k+3)!*(-x)^k))^(1/4))
%Y A303568 Cf. A303565, A303567, A303569.
%K A303568 nonn
%O A303568 0,2
%A A303568 _Seiichi Manyama_, Apr 26 2018