ab + (a + 1) (b + 1) = 2^k diophantine and k+1 prime
Source: INAMO Shortlist 2014 N1
July 9, 2019
number theoryDiophantine equationprime
Problem Statement
(a) Let be an natural number so that the equation does not have a positive integer solution . Show that is a prime number.
(b) Show that there are natural numbers so that is prime numbers and equation has a positive integer solution .