(My English is not very well but I will try to explain myself as good as I can..)
I have 3 questions:
1. Assume 10 is a primitive root of p, a prime number , p!=7.
I need to prove that infinite number of this series :
31 331 3331 ...
is divided by p.
2.Prove that there is no natural number n such that n=2006* fi(n)
(when fi is euler function)
3. This is true that if a is primitive root af n, also is opposite? why?