MathDB
(2^{4n+2}+1)/65 (i) integer, (ii) prime

Source: JBMO 2016 Shortlist N3

October 14, 2017
JBMOnumber theory

Problem Statement

Find all positive integers nn such that the number An=24n+2+165A_n =\frac{ 2^{4n+2}+1}{65} is a) an integer, b) a prime.