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_{l=0}^{k-1} (r+l)^2 (r+l-k)^3
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
