Experiments with the 3n+1 sequence

Links2Go Key Resource Number Theory Topic

Starting with the natural number n, a sequence of numbers will be computed:

• If the number is even, it will be divided by 2.
• If the number is odd, it will be multiplied by 3 and then 1 will be added.

17 is odd, it becomes: 3 * 17 + 1 = 52
52 is even, it becomes: 52 / 2 = 26
26 is even, it becomes 13
13 is odd, it becomes 40
40 is even, it becomes 20
20 is even, it becomes 10
10 is even, it becomes 5
5 is odd, it becomes 16
16 is even, it becomes 8
8 is even, it becomes 4
4 is even, it becomes 2
2 is even, it becomes 1

If the sequence reaches 1, then it is catched in an infinite loop: 1 becomes 4, 4 becomes 2 and 2 finally becomes 1 again.