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 A328046 #9 Feb 16 2025 08:33:58
%S A328046 1,1,7,68,763,9276,118656,1572024,21368155,296187164,4169180104,
%T A328046 59420124472,855590919392,12425933510200,181787367119112,
%U A328046 2676258927443328,39615617922076635,589234154312057436,8801406013366190952,131964659304934491576,1985338775295068132520
%N A328046 G.f.: 1/2 + 1/(1 + AGM(1, sqrt(1-16*x))).
%C A328046 AGM(x,y) = AGM((x+y)/2,sqrt(x*y)) is the arithmetic-geometric mean.
%H A328046 Vaclav Kotesovec, <a href="/A328046/b328046.txt">Table of n, a(n) for n = 0..830</a>
%H A328046 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Arithmetic-GeometricMean.html">Arithmetic-Geometric Mean</a>
%F A328046 a(n) ~ Pi * 16^n / (n * (log(n) + Pi)^2) * (1 - (2*gamma + 8*log(2)) / (log(n) + Pi) + (3*gamma^2 + 48*log(2)^2 + 24*gamma*log(2) - Pi^2/2) / (log(n) + Pi)^2), where gamma is the Euler-Mascheroni constant A001620.
%t A328046 CoefficientList[Series[1/2 + 1/(1 + (Pi*Sqrt[1 - 16*x])/(2*EllipticK[1 - 1/(1 - 16*x)])), {x, 0, 25}], x]
%Y A328046 Cf. A188267.
%Y A328046 Cf. A060691, A081085, A323385.
%K A328046 nonn
%O A328046 0,3
%A A328046 _Vaclav Kotesovec_, Oct 03 2019