Problem: Orac & LCM

Problems and Contests
#1

I don’t quite understand the solution to this problem, could anyone help?

#2

What don’t you get about it?

#3

I don’t have any idea how to solve it. Of course, I tried brute force by calculating all the GCDs and LCMs but got TLE obviously.

#4

Try thinking about it from the perspective of individual prime factors.

#5

For each number of the initial numbers of the ones after the LCM?

#6

The ones after the LCM are defined in terms of the factors of the initial numbers.