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 A277528 #12 Feb 16 2025 08:33:37 %S A277528 4,3,4,9,0,2,8,8,5,6,7,2,8,8,3,7,8,4,8,0,0,2,2,2,5,2,1,4,0,8,3,8,9,5, %T A277528 1,4,9,9,1,6,9,6,1,5,3,3,9,0,0,0,4,4,3,1,4,0,1,3,9,2,2,9,5,3,7,6,1,2, %U A277528 6,2,8,9,6,9,8,7,1,5,7,4,4,0,8,8,5,2,1,1,6,6,7,8,1,7,3,8,1,8,5,1,7,6,7,0,9,8,5,8 %N A277528 Decimal expansion of the seventh derivative of the infinite power tower function x^x^x... at x = 1/2. %H A277528 Alois P. Heinz, <a href="/A277528/b277528.txt">Table of n, a(n) for n = 4..1003</a> %H A277528 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PowerTower.html">Power Tower</a>. %H A277528 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetration">Tetration</a>. %e A277528 4349.0288567288378480022252140838951499169615339... %t A277528 f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[7][f][1/2], 10, 120][[1]] (* _Amiram Eldar_, May 23 2023 *) %Y A277528 Cf. A033917, A104748, A277522, A277523, A277524, A277525, A277526, A277527, A277529, A277530, A277531. %K A277528 nonn,cons %O A277528 4,1 %A A277528 _Alois P. Heinz_, Oct 19 2016