Does this problem have a name?

Question

Recently our lecturer told us that it is an unsolved mathematical problem if the following while loop aka iteration ever terminates. Unfortunately I forgot to ask him what it is called. If someone recognizes this "problem" I would be glad to know what it is called.

Let $n$ be a natural number (if I remember correctly). Calculate the following.

while (n > 1) {
    if (n % 2 == 0) {
        n = n/2;
    } else {
        n = 3 ∗ n + 1;
    }
}

Answer 1

It's called the Collatz Conjecture.

Answer 2

Look for "Collatz-problem" here or in wikipedia