A175594 Numbers having no primitive root.

0, 8, 12, 15, 16, 20, 21, 24, 28, 30, 32, 33, 35, 36, 39, 40, 42, 44, 45, 48, 51, 52, 55, 56, 57, 60, 63, 64, 65, 66, 68, 69, 70, 72, 75, 76, 77, 78, 80, 84, 85, 87, 88, 90, 91, 92, 93, 95, 96, 99, 100, 102, 104, 105, 108, 110, 111, 112, 114, 115, 116, 117, 119, 120, 123

Offset

1,2

Comments

Union of {0} and A033949.

Numbers n such that A046145(n)=0 except n=1.

Links

Table of n, a(n) for n=1..65.

Mathematica

Prepend[Select[Range[2, 123], Not[IntegerQ[PrimitiveRoot[#]]] &], 0] (* Alonso del Arte, Dec 12 2011 *)

Crossrefs

Sequence in context: A050275 A363863 A033949 * A272592 A062373 A180690

Adjacent sequences: A175591 A175592 A175593 * A175595 A175596 A175597

Keyword

nonn

Author

Vladislav-Stepan Malakhovsky & Juri-Stepan Gerasimov, Jul 20 2010

Extensions

Corrected by R. J. Mathar, Oct 15 2011

Corrected by Arkadiusz Wesolowski, Sep 06 2012

Status

approved