MathDB

P156. Saudi Arabia IMO TST

Source:

May 19, 2018

SAUDiophantine Equations

Problem Statement

Let

k

be a positive integer. Prove that there exist integers

x

and

y

, neither of which divisible by

7

, such that \begin{align*} x^2 + 6y^2 = 7^k. \end{align*}