Type: Article
Publication Date: 2013-02-27
Citations: 3
DOI: https://doi.org/10.1093/imrn/rnt026
Suppose that is a set of primes, such that for every , every prime factor of p−1 is also in . We apply a new sieve method to show that either contains all of the primes or the counting function of is O(x1−c) for some c>0, where c depends only on the smallest prime not in . Our proof makes use of results connected with Artin's primitive root conjecture.