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 A246062 #15 Apr 07 2017 01:35:03
%S A246062 1,2,2,28,54,860,2004,33720,86054,1492908,4019452,71101832,198310460,
%T A246062 3555617432,10168382696,184127171952,536496907782,9788598556876,
%U A246062 28937139277804,531135371147368,1588378827366868,29295861148032584,88439788292856856,1637711104368641552
%N A246062 G.f.: sqrt( (1 + sqrt(1+8*x)) / (1 + sqrt(1-8*x)) ).
%C A246062 Unsigned version of A193618.
%H A246062 G. C. Greubel, <a href="/A246062/b246062.txt">Table of n, a(n) for n = 0..1000</a>
%F A246062 G.f.: sqrt( C(2*x)/C(-2*x) ) where C(x) = 1 + x*C(x)^2 is the Catalan function (A000108).
%F A246062 G.f.: exp( Sum_{n>=1} binomial(4*n-2,2*n-1)/2 * (2*x)^(2*n-1)/(2*n-1) ).
%F A246062 G.f. satisfies: A(x)*A(-x) = 1.
%F A246062 a(n) ~ sqrt(sqrt(2)-1)*(1+sqrt(2)-(-1)^n) * 2^(3*n-2) / (sqrt(Pi)*n^(3/2)). - _Vaclav Kotesovec_, Aug 25 2014
%e A246062 G.f.: A(x) = 1 + 2*x + 2*x^2 + 28*x^3 + 54*x^4 + 860*x^5 + 2004*x^6 +...
%t A246062 CoefficientList[Series[Sqrt[(1 + Sqrt[1 + 8*x])/(1 + Sqrt[1 - 8*x])], {x, 0, 20}], x] (* _Vaclav Kotesovec_, Aug 25 2014 *)
%o A246062 (PARI) {a(n)=polcoeff( sqrt((1+sqrt(1+8*x +O(x^(n+2))))/(1+sqrt(1-8*x +O(x^(n+2))))),n)}
%o A246062 for(n=0,30,print1(a(n),", "))
%Y A246062 Cf. A193618, A000108.
%K A246062 nonn
%O A246062 0,2
%A A246062 _Paul D. Hanna_, Aug 24 2014