While researching for my group’s Goldbach Conjecture Presentation, I came across Artin’s Conjecture.

Artin’s Conjecture states: If r is a nonsquare integer other than -1, then there are infinitely many prime numbers p for which r is a primitive root mod p.

I learned that David Rodney Heath-Brown (British Mathematician) gave an approximate solution to Artin’s conjecture on primitive roots, to the effect that out of 3, 5, 7 (or any three similar multiplicatively-independent square-free integers), one at least is a primitive root mod p, for infinitely many prime numbers p.

Artin’s Conjecture is also mentioned in our textbook if anyone is interested!