MathDB
2021 LMT Spring Division A Problem 16

Source:

October 22, 2021

Problem Statement

Find the number of ordered pairs (a,b)(a,b) of positive integers less than or equal to 2020 such that \gcd(a,b)>1   \text{and}   \frac{1}{\gcd(a,b)}+\frac{a+b}{\text{lcm}(a,b)} \geq 1.
Proposed by Zachary Perry