Finds numbers which take a long time to reach 1 in collatz process. Explanation here: https://youtu.be/PrWXtgHCxNk
Download or clone the repository and run the collatz_length.py file. It should generate the collatz_lengths.csv spreadsheet automatically. Change the last_to_check variable to run the program for longer.
3, 7, 9, 27, 230631, 626331, 837799, 1723519, 3732423, 6649279, 8400511, 63728127, 942488749153153, 7579309213675935, 93571393692802302, 931386509544713451