A215704 n-th derivative of ((x^x)^x)^x at x=1.

1, 1, 6, 27, 156, 1110, 8322, 70098, 646272, 6333336, 66712680, 745731360, 8780828328, 108873486072, 1413807287760, 19157627737080, 270460073295360, 3965693824244160, 60266513065134528, 947644484349584448, 15389579447794454400, 257702782790624613120

Offset: 0

Author

Alois P. Heinz, Aug 21 2012

Keywords

• sign

Comments

Also n-th derivative of x^(x^3) at x=1.

First term < 0: a(57).

Links

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

Crossrefs

Column k=5 of A215703.

Cf. A005727, A179230, A179405, A215524.

Programs

Maple

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

Formula

E.g.f.: (x+1)^((x+1)^3).