MathDB
Set closed under gcd

Source: Iberoamerican 2018 Problem 4

September 26, 2018
number theorygreatest common divisor

Problem Statement

A set XX of positive integers is said to be iberic if XX is a subset of {2,3,…,2018}\{2, 3, \dots, 2018\}, and whenever m,nm, n are both in XX, gcd⁡(m,n)\gcd(m, n) is also in XX. An iberic set is said to be olympic if it is not properly contained in any other iberic set. Find all olympic iberic sets that contain the number 3333.
Back to ProblemsView on AoPS