A288636 Height of power-tower factorization of n. Row lengths of A278028.

0, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1

Offset

1,4

Comments

After a(1)=0 this sequence has many terms equal to A089723. It first differs at a(64)=2, A089723(64)=4.

First positions of a(n) = {0, 1, 2, 3, 4} are n = {1, 2, 4, 16, 65536}. - Michael De Vlieger, Nov 24 2017

Links

Michael De Vlieger, Table of n, a(n) for n = 1..65536

Mathematica

a[n_] := If[n == 1, 0, 1+a[GCD @@ FactorInteger[n][[All, 2]]]];
Array[a, 100]

Crossrefs

Cf. A007916, A089723, A164337, A277562, A277564, A278028.

Sequence in context: A180601 A331048 A341593 * A089723 A363741 A305253

Adjacent sequences: A288633 A288634 A288635 * A288637 A288638 A288639

Keyword

nonn

Author

Gus Wiseman, Jun 12 2017

Status

approved