A215708 n-th derivative of (x^(x^x))^(x^x) at x=1.

1, 1, 4, 24, 148, 1180, 10428, 106876, 1198160, 14843808, 198832320, 2877693984, 44545268832, 734929736736, 12852051257472, 237372559264320, 4614124211454720, 94103610003019008, 2008507968212696064, 44748953208031094784, 1038646472528272158720

Offset: 0

Author

Alois P. Heinz, Aug 21 2012

Keywords

• sign

Comments

Also n-th derivative of x^((x^x)^2) at x=1.

First term < 0: a(175).

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..400

Crossrefs

Column k=11 of A215703.

Cf. A005727, A179230, A179405, A215524.

Programs

Maple

a:= n-> n!*coeff(series(subs(x=x+1, x^((x^x)^2) ), x, n+1), x, n):
seq(a(n), n=0..25);

Formula

E.g.f.: (x+1)^((x+1)^(2*x+2)).