Introduction

In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. (Wikipedia)

Project #1

Create and interactive program that

1. ask the user for a non-negative integer
2. validate the user's input
3. calculate the integer's factorial and double factorial
4. display the integer, factorial, and double factorial
5. loop

Read the documentation of the math.factorial function.

Links

Factorial (Wikipedia)

Double factorial (Wikipedia)