60 is written on a blackboard, divisors related
Source: (2021-) 2022 XV 15th Dürer Math Competition Finals Day 2 E16
December 12, 2022
number theoryDivisors
Problem Statement
The number is written on a blackboard. In every move, Andris wipes the numbers on the board one by one, and writes all its divisors in its place (including itself). After such moves, how many times will appear on the board?