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 A089156 #15 Sep 28 2019 06:07:41
%S A089156 0,16,576,25600,1254400,65028096,3497066496,192980975616,
%T A089156 10855179878400,619683355033600,35792910586740736,2087229562810269696,
%U A089156 122682715414070296576,7259332273021911040000,432004345063916175360000,25835779854133582469529600
%N A089156 a(n) = A069722(n+1)^2.
%F A089156 G.f.: 1/AGM(1, (1-64*x)^(1/2)).
%F A089156 E.g.f.: 1 + Sum[n>=0, a(n)*x^(2n)/(2n)! ] = BesselI(0, 4x)^2. - _Ralf Stephan_, Jan 11 2005
%F A089156 From _Vaclav Kotesovec_, Sep 28 2019: (Start)
%F A089156 For n > 0, a(n) = 2^(2*n) * binomial(2*n, n)^2.
%F A089156 a(n) ~ 2^(6*n) / (Pi*n). (End)
%t A089156 Flatten[{0, Table[2^(2*n) * Binomial[2*n, n]^2, {n, 1, 20}]}] (* _Vaclav Kotesovec_, Sep 28 2019 *)
%t A089156 CoefficientList[Series[-1 + 2*EllipticK[1 - 1/(1 - 64*x)] / (Pi*Sqrt[1 - 64*x]), {x, 0, 20}], x] (* _Vaclav Kotesovec_, Sep 28 2019 *)
%Y A089156 Cf. A069722.
%K A089156 nonn
%O A089156 0,2
%A A089156 _Benoit Cloitre_, Jan 03 2004