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 A221566 #25 Jul 02 2023 16:53:01 %S A221566 7,7,4,0,4,4,3,7,6,2,4,2,1,4,8,8,5,5,5,9,6,1,7,4,2,6,7,9,2,3,1,2,5,9, %T A221566 3,5,5,2,5,5,2,5,6,9,4,6,6,6,0,3,9,7,7,9,2,4,1,8,9,5,0,3,5,5,5,3,6,0, %U A221566 8,9,2,3,9,5,0,1,3,0,5,7,9,2,4,7,8,6,8,7,0,0,9,5,0,0,5,8,7,4,9,5,8,1,3,5,8 %N A221566 Decimal expansion of b^b^b^..., where b equals e-2 (A001113). %C A221566 Inspired by A225053. %e A221566 0.7740443762421488555961742679231259355255256946660397792418950355... %t A221566 b = N[E - 2, 128]; f[n_] := Nest[b^# &, b, n]; RealDigits[ f[186], 10, 111][[1]] %t A221566 RealDigits[ -LambertW[ -Log[E - 2]]/Log[E - 2], 10, 105][[1]] %Y A221566 Cf. A225053. %K A221566 nonn,cons %O A221566 0,1 %A A221566 _Vladimir Reshetnikov_ and _Robert G. Wilson v_, May 05 2013