Shortlist 2017/N6
Source:
July 10, 2018
number theoryIMO ShortlistVieta Jumping
Problem Statement
Find the smallest positive integer or show no such exists, with the following property: there are infinitely many distinct -tuples of positive rational numbers such that both
a_1+a_2+\dots +a_n \text{and} \frac{1}{a_1} + \frac{1}{a_2} + \dots + \frac{1}{a_n}
are integers.