Collatz conjecture is an unsolved problem in mathematics. It states the following.
"You start with an integer of your choice. You divide it by 2 if this integer is even, else you multiply it by 3 and add 1. Do the same with the outcome of this. Keep doing this. Eventually you get 1."
For example, if our chosen integer is 13, then we get the following sequence as a result of iteration suggested above.
13 --> 40 --> 20 --> 10 --> 5 --> 16 --> 8 --> 4 --> 2 --> 1
Let us call it Collatz sequence for 13. While a mathematical proof for Collatz conjecture has not yet been obtained, computers have checked its correctness till 87 x 2**60. What is equally interesting is the number of steps it takes for an integer to reach 1. We shall call it the length of Collatz sequence. For example, this length is 9, if we start with 13.
Now, with that as background, I pose the following challenge.
Use your Python skills to find a Collatz sequence of really large length.