MathDB
Find the maximum value

Source: Argentina TST 2009

May 15, 2009
inequalitiesClevermath

Problem Statement

Let a1,a2,...,a300 a_1, a_2, ..., a_{300} be nonnegative real numbers, with \sum_{i\equal{}1}^{300} a_i \equal{} 1. Find the maximum possible value of ij,ijaiaj \sum_{i \neq j, i|j} a_ia_j.