Maths/Factorial have more minimal side effects.

[Eji4h]

At Contribution Guidelines have minimal side effects is one of What is an Algorithm. I think code can improve by refactor to functional programming.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

Please reopen this issue once you commit the changes requested or make improvements on the code. Thank you for your contributions.