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.
summation 2 to infinity of ( 3n * (n-1) * 0.4^2 * 0.6^(n-2))
summation 2 to infinity of ( 3n * (n-1) * 0.4^2 * 0.6^(n-2))
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random