OFFSET
1,1
COMMENTS
These are the counterexamples mentioned in the Sep 12 2012 comment from Bruno Berselli in A059245.
EXAMPLE
4421 is in the sequence since it is prime, it is congruent to 1 (mod 13), and x^13 == 2 (mod 4421) has the solution x = 162. - Michael B. Porter, Aug 26 2016
MATHEMATICA
Quiet@ Select[Prime@ Range[10^4], And[Mod[#, 13] == 1, IntegerQ@ PowerMod[2, 1/13, #]] &] (* Michael De Vlieger, Aug 10 2016 *)
PROG
(PARI) forprime(p=1, 1e6, if(Mod(p, 13)==1 && ispower(Mod(2, p), 13), print1(p, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Aug 08 2016
STATUS
approved