recursion 4

Create a pseudo code (not actual coding) routine/function that will ask the user for a number, and then using recursion, generate the factorial of that number.
Create fully documented pseudo code to prompt for a number and generate the factorial, including error and bound checking. Basically putting comments within the pseudo code and than a discussion on what recursion is, where its used.
Create a test plan to show how the program runs and can be executed, this can be simplistic. Basically asking what are the test cases that you have to make sure this works for and what the expected outcome is?