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.
Σ 2/( (k-2)n² - (k-4)n ), [n=1,∞], for k=6
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random