%I
%S 5,7,13,23,25,29,37,47,49,53,61,71,79,101,103,125,149,167,169,173,181,
%T 191,197,199,239,263,269,271,293,311,317,343,349,359,367,373,383,389,
%U 421,461,463,479,487,503,509,529,541,557,599,607,613,625,647,653,661
%N Numbers with primitive root 2.
%H Vincenzo Librandi, <a href="/A167798/b167798.txt">Table of n, a(n) for n = 1..1000</a>
%t pr=2; Select[Range[2,2000], MultiplicativeOrder[pr,# ] == EulerPhi[ # ] &]
%Y Cf. A105874 (primes with primitive root 2)
%K nonn
%O 1,1
%A _T. D. Noe_, Nov 12 2009
