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%I #11 Mar 31 2024 15:03:19
%S 13,17,19,23,41,47,61,67,71,89,109,113,137,157,167,211,229,233,257,
%T 263,277,283,331,359,373,383,397,401,449,479,503,521,523,547,569,593,
%U 599,613,619,641,647,661,691,709,719,733,739,743,757,761,787,809,811,829,839,853
%N Primes for which -6 is a primitive root.
%H Vincenzo Librandi, <a href="/A105878/b105878.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=-6; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
%o (PARI) is(n)=isprime(n) && n>7 && znorder(Mod(-6,n))==n-1 \\ _Charles R Greathouse IV_, Feb 23 2017
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Apr 24 2005