There's a Math Problem That's Unsolved for Over 350 Years - Apparently.
The problem, known as the "Collatz Conjecture" or "3x+1 problem", was first proposed in the 18th century by mathematician Christian Goldbach. It's a simple-sounding sequence: start with any positive integer, if it's even, divide it by 2, if it's odd, multiply it by 3 and add 1. The conjecture claims that no matter what number you start with, this process will always reach 1. Despite much effort, a formal proof or counterexample has yet to be found.