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.
(4 Sum[((-1)^k/(2 k + 1))((goldenratio^(-2k-1))*goldenratio^(-6k-3)), {k, 0, 70}])
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random