USAMO 1984 Problem 2 - Geometric Mean
Source: USAMO 1984 Problem 2
August 16, 2011
AMCUSA(J)MOUSAMOnumber theory unsolvednumber theory
Problem Statement
The geometric mean of any set of non-negative numbers is the -th root of their product. (\text{i}) For which positive integers is there a finite set of distinct positive integers such that the geometric mean of any subset of is an integer?
(\text{ii}) Is there an infinite set of distinct positive integers such that the geometric mean of any finite subset of is an integer?