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 A277527 #12 Feb 16 2025 08:33:37 %S A277527 2,7,7,4,4,1,3,2,0,3,5,4,0,6,1,7,9,1,0,5,8,5,6,9,5,5,1,3,9,5,9,8,4,7, %T A277527 5,1,4,8,8,0,3,0,9,1,5,0,5,9,4,7,0,3,9,0,8,4,1,3,5,8,3,0,8,7,8,4,7,9, %U A277527 7,2,0,0,0,6,0,7,2,2,5,8,9,9,7,2,5,1,5,2,7,8,1,3,3,0,5,0,1,0,8,0,0,8,8,6,0 %N A277527 Decimal expansion of the sixth derivative of the infinite power tower function x^x^x... at x = 1/2, negated. %H A277527 Alois P. Heinz, <a href="/A277527/b277527.txt">Table of n, a(n) for n = 3..1002</a> %H A277527 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PowerTower.html">Power Tower</a>. %H A277527 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetration">Tetration</a>. %e A277527 -277.441320354061791058569551395984751488030915... %t A277527 f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[6][f][1/2], 10, 120][[1]] (* _Amiram Eldar_, May 23 2023 *) %Y A277527 Cf. A033917, A104748, A277522, A277523, A277524, A277525, A277526, A277528, A277529, A277530, A277531. %K A277527 nonn,cons %O A277527 3,1 %A A277527 _Alois P. Heinz_, Oct 19 2016