Fermat's Theorem
We all know fermat's theorem that states: if p is a prime and (p,a)=1 then p divides a^(p1)1. I noticed that p divides also: a^k(p1)1. Is this a well known characteristic?
Second question: what about the infinite sums c, and in particularly when c=1 ? like 11+11+...
Last question: does anybody know if new progresses were made in defining the necessary conditions for a function to be defined with a Fourier series?
Greetings
