This is a process that you can test any number with, where you must divide the number by 2 if its even, or multiply by 3 and add 1 if its odd. The rule states that every number will always become a loop, from the number 4, to 2, and to 1, then back to 4. This script will try (and most likely fail) to find a solution!
I became interested after watching "The Simplest Math Problem No One Can Solve - Collatz Conjecture" by Veritasium on youtube.