Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
((n−k)!(k−1)!) * (n−k−1)!k!/gcd((n−k)!(k−1)!, (n−k)!(k−1)! )
((n−k)!(k−1)!) * (n−k−1)!k!/gcd((n−k)!(k−1)!, (n−k)!(k−1)! )
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
