# The Collatz-Conjecture

## The Problem¶

This is a famous and not yet fully solved problem in mathmatics. Here are the rules:

- Start with any
**positive integer**number*x* - If
*x*is even, assign*x ← x/2* - If
*x*is odd, assign*x ← 3x + 1*

Eventually your sequence will end up in the loop 4 → 2 → 1 → 4 … (The unsolved part is that there is no proof yet that this always happens.)

## Now you!¶

Implement a loop that generates and prints the sequence for any given positive starting number.
You can either set the starting value in a variable at the beginning of your program or read it from a user input.
The loop should stop if *x* reaches one of the three numbers (4, 2, or 1) that are known to form an endless cycle.

**Example Output:**

## Hint

To check if a number is even, the modulo-operator (written as `%`

in Python) might be very helpful.
It calculates the remainder of a whole-number division.

For example `13 // 3 == 4`

and since `4 * 3 == 12`

that leaves a reminder of `1`

to get to the original `13`

.
Therefore, `13 % 3 == 1`

.