A167795 Numbers with primitive root 7.

2, 4, 5, 10, 11, 13, 17, 22, 23, 26, 34, 41, 46, 61, 67, 71, 79, 82, 89, 97, 101, 107, 121, 122, 127, 134, 142, 151, 158, 163, 169, 173, 178, 179, 194, 202, 211, 214, 229, 239, 241, 242, 254, 257, 263, 269, 289, 293, 302, 326, 338, 346, 347, 349, 358, 359, 379

Offset: 1

Author

T. D. Noe, Nov 12 2009

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A019337 (primes with primitive root 7)

Programs

Mathematica

pr=7; Select[Range[2,2000], MultiplicativeOrder[pr,# ] == EulerPhi[ # ] &]

PARI

is(n)=if(n%7==0, return(0)); my(p=eulerphi(n)); znorder(Mod(7, n), p)==p \\ Charles R Greathouse IV, Jan 04 2025