all integers that can occur as the average of a centenary set
Source: Dutch NMO 2022 p2
November 17, 2022
number theory
Problem Statement
A set consisting of at least two distinct positive integers is called centenary if its greatest element is . We will consider the average of all numbers in a centenary set, which we will call the average of the set. For example, the average of the centenary set is and the average of the centenary set is . Determine all integers that can occur as the average of a centenary set.