MathDB
2024 BxMO P4

Source: 2024 BxMO P4

April 28, 2024
number theory

Problem Statement

For each positive integer nn, let rad(n)rad(n) denote the product of the distinct prime factors of nn. Show that there exists integers a,b>1a,b > 1 such that gcd(a,b)=1gcd(a,b)=1 and rad(ab(a+b))<a+b20242024rad(ab(a+b)) < \frac{a+b}{2024^{2024}}.
For example, rad(20)=rad(225)=25=10rad(20)=rad(2^2\cdot 5)=2\cdot 5=10.