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 A277529 #12 Feb 16 2025 08:33:37 %S A277529 5,0,1,0,9,2,7,6,2,7,5,0,3,6,6,9,6,8,9,5,8,6,8,0,1,7,2,3,5,3,2,2,9,4, %T A277529 5,1,2,7,2,1,8,3,9,4,2,3,8,3,2,4,2,6,2,4,4,6,0,2,8,9,9,9,1,1,8,5,8,4, %U A277529 6,3,2,4,1,1,0,1,8,9,6,2,0,2,8,2,1,0,6,6,7,3,8,4,1,4,3,1,6,6,8,7,3,6,1,0,8,7 %N A277529 Decimal expansion of the eighth derivative of the infinite power tower function x^x^x... at x = 1/2, negated. %H A277529 Alois P. Heinz, <a href="/A277529/b277529.txt">Table of n, a(n) for n = 5..1004</a> %H A277529 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PowerTower.html">Power Tower</a>. %H A277529 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetration">Tetration</a>. %e A277529 -50109.2762750366968958680172353229451272183942... %t A277529 f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[8][f][1/2], 10, 120][[1]] (* _Amiram Eldar_, May 23 2023 *) %Y A277529 Cf. A033917, A104748, A277522, A277523, A277524, A277525, A277526, A277527, A277528, A277530, A277531. %K A277529 nonn,cons %O A277529 5,1 %A A277529 _Alois P. Heinz_, Oct 19 2016