The Collatz conjecture is a conjecture (an idea which many people think is likely) in mathematics. It is named after Lothar Collatz. He first proposed it in 1937. It is about what happens when something is done repeatedly (over and over) starting at some positive integer n:
- If n is even (divisible by two), n is halved (divide by two = take its half).
- If n is odd (not divisible by two), n is changed to .
The conjecture states that if n is positive, n will always reach one. The problem is computationally verified for all numbers below . Here is an example sequence: