login
A277528
Decimal expansion of the seventh derivative of the infinite power tower function x^x^x... at x = 1/2.
10
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, 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, 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
OFFSET
4,1
LINKS
Eric Weisstein's World of Mathematics, Power Tower.
Wikipedia, Tetration.
EXAMPLE
4349.0288567288378480022252140838951499169615339...
MATHEMATICA
f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[7][f][1/2], 10, 120][[1]] (* Amiram Eldar, May 23 2023 *)
KEYWORD
nonn,cons
AUTHOR
Alois P. Heinz, Oct 19 2016
STATUS
approved