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 A104123 #7 Jan 13 2017 12:40:43 %S A104123 4,6,6,9,2,0,1,6,0,9,1,8,3,4,9,2,4,5,1,4,5,0,6,6,1,8,9,4,0,5,2,3,3,0, %T A104123 6,1,9,5,1,6,9,6,6,1,0,5,5,5,8,6,9,4,3,6,6,2,9,7,8,2,7,2,5,3,9,7,8,4, %U A104123 4,7,0,7,2,7,7,6,2,6,6,7,4,8,0,6,6,9,9,8,4,8,0,4,1,8,4,4,3,2,0,1,4,8,7,4,0 %N A104123 Decimal expansion of the constant c = sqrt((137 - 1/(57+sqrt(Pi)/10))/(2*Pi)), an approximation to the Feigenbaum bifurcation velocity constant delta (A006890). %C A104123 c - delta = 0.000000000080501779597..., Gamma(delta) - InverseGamma(1/(c-delta)) = 0.50050037514..., log(log(1/(c-d))) - Pi = 0.00440025013324... %H A104123 G. C. Greubel, <a href="/A104123/b104123.txt">Table of n, a(n) for n = 1..5000</a> %e A104123 4.669201609183492451450661894052330619516966105558694366297827... %t A104123 RealDigits[Sqrt[(137 - 1/(57 + Sqrt[Pi]/10))/(2 Pi)], 10, 110][[1]] %o A104123 (PARI) sqrt((137 - 1/(57 + sqrt(Pi)/10))/(2*Pi)) \\ _G. C. Greubel_, Jan 13 2017 %Y A104123 Cf. A006890. %K A104123 cons,nonn %O A104123 1,1 %A A104123 _Gerald McGarvey_, Mar 06 2005