A167806 - OEIS

%I #14 Nov 25 2014 13:34:19

%S 3,17,29,31,43,61,67,71,83,97,107,109,113,149,151,163,181,191,193,199,

%T 227,229,233,257,269,283,289,307,311,313,337,347,359,389,431,433,439,

%U 443,461,467,479,509,523,541,563,577,587,593,599,631,683,701,709,719

%N Numbers with primitive root -10.

%C Note that the term 289 is not a prime and therefore does not appear in A007348. - _Robert G. Wilson v_, Aug 18 2014

%H Vincenzo Librandi, <a href="/A167806/b167806.txt">Table of n, a(n) for n = 1..1000</a>

%t pr=-10; Select[Range[2,2000], MultiplicativeOrder[pr,# ] == EulerPhi[ # ] &]

%o (PARI) is(n)=if(gcd(n,10)>1, return(0)); my(p=eulerphi(n)); znorder(Mod(-10,n),p)==p \\ _Charles R Greathouse IV_, Nov 25 2014

%Y Cf. A007348 (primes with primitive root -10).

%K nonn

%O 1,1

%A _T. D. Noe_, Nov 12 2009