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A277525
Decimal expansion of the fourth derivative of the infinite power tower function x^x^x... at x = 1/2, negated.
10
1, 7, 2, 9, 6, 3, 7, 6, 7, 7, 6, 7, 5, 5, 4, 3, 4, 1, 4, 4, 7, 5, 9, 9, 4, 3, 6, 6, 8, 6, 0, 8, 3, 4, 0, 4, 1, 1, 3, 7, 8, 5, 9, 2, 4, 8, 5, 8, 7, 6, 2, 4, 7, 5, 4, 3, 6, 2, 8, 4, 5, 2, 7, 3, 6, 5, 9, 6, 9, 2, 3, 4, 8, 6, 2, 8, 9, 4, 3, 3, 4, 5, 2, 1, 7, 5, 6, 7, 1, 2, 3, 8, 4, 8, 3, 8, 7, 0, 4, 5, 2, 4, 4, 0, 8, 8
OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Power Tower.
Wikipedia, Tetration.
EXAMPLE
-1.7296376776755434144759943668608340411378592485876...
MATHEMATICA
f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[4][f][1/2], 10, 120][[1]] (* Amiram Eldar, May 23 2023 *)
KEYWORD
nonn,cons
AUTHOR
Alois P. Heinz, Oct 19 2016
STATUS
approved