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 A266390 #33 Jan 13 2016 00:34:23 %S A266390 2,7,2,2,6,8,7,7,7,6,8,5,8,8,5,7,6,4,6,7,0,7,9,4,5,8,0,5,1,4,9,4,4,5, %T A266390 8,2,8,7,4,8,9,8,0,1,5,8,7,7,8,6,8,3,6,0,1,0,7,2,4,0,8,6,9,4,3,6,1,9, %U A266390 3,3,4,9,7,6,2,6,2,3,1,3,7,2,1 %N A266390 Decimal expansion of exponential growth rate of number of labeled planar graphs on n vertices. %H A266390 Gheorghe Coserea, <a href="/A266390/b266390.txt">Table of n, a(n) for n = 2..51000</a> %H A266390 Omer Giménez, Marc Noy, <a href="http://dx.doi.org/10.1007/978-3-0348-7915-6_12">Estimating the Growth Constant of Labelled Planar Graphs</a>, Mathematics and Computer Science III, Part of the series Trends in Mathematics 2004, pp. 133-139. %H A266390 Omer Gimenez, Marc Noy, <a href="http://dx.doi.org/10.1090/S0894-0347-08-00624-3">Asymptotic enumeration and limit laws of planar graphs</a>, J. Amer. Math. Soc. 22 (2009), 309-329. %F A266390 Equals 1/R(A266389), where function t->R(t) is defined in the PARI code. %F A266390 A066537(n) ~ A266391 * A266390^n * n^(-7/2) * n!. %e A266390 27.2268777685... %o A266390 (PARI) %o A266390 A266389= 0.6263716633; %o A266390 A1(t) = log(1+t) * (3*t-1) * (1+t)^3 / (16*t^3); %o A266390 A2(t) = log(1+2*t) * (1+3*t) * (1-t)^3 / (32*t^3); %o A266390 A3(t) = (1-t) * (185*t^4 + 698*t^3 - 217*t^2 - 160*t + 6); %o A266390 A4(t) = 64*t * (1+3*t)^2 * (3+t); %o A266390 A(t) = A1(t) + A2(t) + A3(t) / A4(t); %o A266390 R(t) = 1/16 * sqrt(1+3*t) * (1/t - 1)^3 * exp(A(t)); %o A266390 1/R(A266389) %Y A266390 Cf. A066537, A266389, A266391. %K A266390 nonn,cons %O A266390 2,1 %A A266390 _Gheorghe Coserea_, Dec 28 2015