Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

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;
    }
}
share|improve this question
3  
As you will find when you read the Wikipedia article, it has lots of names. –  André Nicolas Feb 4 '13 at 7:07
add comment

2 Answers

up vote 7 down vote accepted

It's called the Collatz Conjecture.

share|improve this answer
add comment

Look for "Collatz-problem" here or in wikipedia

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.