%I #9 Mar 31 2024 15:13:46

%S 3,17,29,31,43,71,73,79,83,97,101,107,109,137,149,151,191,193,227,229,

%T 233,257,269,271,283,307,311,347,349,353,359,389,421,431,433,439,443,

%U 461,467,479,509,523,541,563,577,587,593,599,617,661,673,683,701,709,719,751,787

%N Primes for which -40 is a primitive root.

%H Vincenzo Librandi, <a href="/A105912/b105912.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Pri#primes_root">Index entries for primes by primitive root</a>

%t pr=-40; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Apr 24 2005