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.
sum (n!/(i! * (n-i)!) * (sum ( i!/(j! * (i-j)!) * j ),j=1 to i ) ), i = 1 to n
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random