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 A303537 #25 Nov 14 2023 02:10:46
%S A303537 1,2,2,12,22,124,276,1496,3686,19436,51068,263720,724860,3681880,
%T A303537 10466920,52450992,153093254,758495564,2261603564,11096526344,
%U A303537 33676743956,163842737928,504738342808,2437418983888,7605947276508,36487283224952,115140704639576
%N A303537 Expansion of ((1 + 4*x)/(1 - 4*x))^(1/4).
%C A303537 Let ((1 + k*x)/(1 - k*x))^(1/k) = a(0) + a(1)*x + a(2)*x^2 + ...
%C A303537 Then n*a(n) = 2*a(n-1) + k^2*(n-2)*a(n-2) for n > 1.
%H A303537 Seiichi Manyama, <a href="/A303537/b303537.txt">Table of n, a(n) for n = 0..1000</a>
%F A303537 a(n) ~ 2^(2*n + 1/4) / (Gamma(1/4) * n^(3/4)). - _Vaclav Kotesovec_, Apr 26 2018
%F A303537 n*a(n) = 2*a(n-1) + 4^2*(n-2)*a(n-2) for n > 1.
%F A303537 G.f.: A(x)=F(x*G(x^2)), where F(x) is the g.f. for A063886, and G(x) is the g.f. for A151403. - _Alexander Burstein_, Nov 13 2023
%t A303537 CoefficientList[Series[Surd[(1+4x)/(1-4x),4],{x,0,40}],x] (* _Harvey P. Dale_, Jul 25 2021 *)
%o A303537 (PARI) N=66; x='x+O('x^N); Vec(((1+4*x)/(1-4*x))^(1/4))
%Y A303537 Cf. A063886, A081654, A151403, A303538.
%K A303537 nonn
%O A303537 0,2
%A A303537 _Seiichi Manyama_, Apr 25 2018