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 A277531 #12 Feb 16 2025 08:33:37 %S A277531 1,4,1,0,9,5,0,8,6,0,4,5,7,8,2,5,2,1,6,6,7,4,8,0,7,9,5,6,6,6,2,1,3,8, %T A277531 6,1,1,5,9,2,7,6,0,7,4,9,5,2,5,0,6,8,9,5,9,1,6,1,0,1,8,4,7,0,8,2,4,0, %U A277531 0,4,4,5,8,4,4,8,8,7,2,4,0,0,8,9,3,2,4,1,1,6,2,1,3,3,3,3,4,9,8,0,6,7,0,5,3 %N A277531 Decimal expansion of the tenth derivative of the infinite power tower function x^x^x... at x = 1/2, negated. %H A277531 Alois P. Heinz, <a href="/A277531/b277531.txt">Table of n, a(n) for n = 8..1007</a> %H A277531 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PowerTower.html">Power Tower</a>. %H A277531 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetration">Tetration</a>. %e A277531 -14109508.6045782521667480795666213861159276... %t A277531 f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[10][f][1/2], 10, 120][[1]] (* _Amiram Eldar_, May 23 2023 *) %Y A277531 Cf. A033917, A104748, A277522, A277523, A277524, A277525, A277526, A277527, A277528, A277529, A277530. %K A277531 nonn,cons %O A277531 8,2 %A A277531 _Alois P. Heinz_, Oct 19 2016