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 A306883 #12 May 08 2019 15:46:11
%S A306883 5,9,3,2,3,7,2,9,7,7,6,9,7,2,8,4,6,4,5,5,2,0,6,0,1,9,7,9,4,7,0,8,1,7,
%T A306883 0,0,4,2,3,8,8,3,8,8,2,3,6,2,1,6,5,7,7,7,4,5,7,6,7,1,2,8,6,0,9,6,9,9,
%U A306883 5,0,5,8,7,1,0,6,7,8,5,7,9,1,5,2,9,0,7,1,4,3,3,3,5,3,7,9,4,8,8,4,9,4,3,2,5,4,3,5,1
%N A306883 Decimal expansion of the minimum value of the function f(x) = x^x^x^x.
%C A306883 The minimum value of the function x^x^x^x which is obtained for x equal to A306579.
%e A306883 0.5932372977697284645520601979470817...
%t A306883 n = 500;
%t A306883 (FindMinimum[x^x^x^x, {x, 0.34}, WorkingPrecision -> 3 n][[1]] // RealDigits)[[1]][[;; n]]
%o A306883 (PARI) my(y = solve(x=0.1, 1, 1 + x^x*log(x)*(1 + x*log(x)*(1 + log(x))))); y^y^y^y \\ _Michel Marcus_, Mar 27 2019
%Y A306883 Cf. A306579.
%K A306883 nonn,cons
%O A306883 0,1
%A A306883 _Philipp O. Tsvetkov_, Mar 15 2019