OFFSET
1,1
COMMENTS
If a prime p has period n, then p divides 10^m - 1 for all m divisible by n. Therefore the sequence together with 3 is the complement in the primes of A072859.
PROG
(Magma) [2] cat [p: p in PrimesInInterval(5, 353) | not IsPrime(Modorder(10, p))];
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Arkadiusz Wesolowski, Oct 25 2014
STATUS
approved