Thread: Some arithmetic... View Single Post
 2014-07-14, 23:30 #2 Zeta-Flux     May 2003 7·13·17 Posts Better than that, the Wieferich condition is equivalent to $2^{(p-1)/2} \equiv \pm 1\pmod{p^2}$. This makes it slightly easier to test for the condition. The only place I know of where the Wieferich condition is really useful is in the first case of Fermat's last theorem and in the solution to Catalan's conjecture.