I have the following question:
Given an integer $n \ge 1 $ which is not a square, does there exist a prime number $p$ for which $n$ is a primitive root modulo $p?$
It is easy to see that if $n$ is a square, then it is not a primitive root modulo any odd prime. Artin conjectures that for any such $n$ there are infinitely many such primes, but is it known that at least one such prime always exists?