IMO Shortlist 2007 problem N1
Dodao/la:
arhiva2. travnja 2012. Find all pairs of natural numbers
such that
divides
.
Author: Stephan Wagner, Austria
%V0
Find all pairs of natural numbers $(a, b)$ such that $7^a - 3^b$ divides $a^4 + b^2$.
Author: Stephan Wagner, Austria
Izvor: Međunarodna matematička olimpijada, shortlist 2007