Computer programs by Shlomi Fish to investigate the Collatz Conjecture .

Reading from the wikipedia page:

The conjecture can be summarized as follows. Take any positive integer n. If n
is even, divide it by 2 to get n / 2. If n is odd, multiply it by 3 and add 1
to obtain 3n + 1. Repeat the process (which has been called "Half Or Triple
Plus One", or HOTPO[7]) indefinitely. The conjecture is that no matter what
number you start with, you will always eventually reach 1.