Problem of the Week 1061
A Fractional Sum
Given a positive integer n, which integers can arise as the following sum
1/x1 + 2/x2 + 3/x3 + ... + n/xn
where xi is a strictly increasing sequence of positive integers?
Source: 13th Irish Olympiad, Crux Mathematicorum May 2006.
© Copyright 2006 Stan Wagon. Reproduced with permission.