Data Paths

This is a simple calculator, I've came up with the idea when I was taking a "System Analysis Design and Project" class in college. The formula this calculator uses is commonly used to analyze permutations and combinations of values. This formula can be used to calculate the number of data paths within a network. For a small network you can sketch and count the paths, but that is a little harder to do when you have hundreds of nodes, and that's why I've made this calculator.
I remember searching for one on the market at the time I was taking the class and couldn't find any. I'm not putting this calculator on the market to get the most amount of downloads; I'm just hoping it will give someone the kind of help I was looking for.
Thanks,