Collatz Conjecture

Collatz Conjecture

The collatz-conjecture is a simple-looking but still unsolved math problem.
Given any number n, will it always break down to 1 after applying the two rules?
The rules:

  • If n is even, divide n by 2
  • If n is odd, multiply by 3 and add 1

More on this problem, the history and reasoning, and why it hasn't been solved yet: here

This is how the rules above could look like in PHP:


$n = 27;

while ($n !== 1) {

    if ($n % 2 === 0) {

        $n = $n / 2;

    } else {

        $n = 3 * $n + 1;

    }

}

Try it out: