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\limits_{k=0}^{\infty} \binom{(2n-1)/4}{k} \frac{(-1)^k}{2k+1}
\sum\limits_{k=0}^{\infty} \binom{(2n-1)/4}{k} \frac{(-1)^k}{2k+1}
Natural Language
Math Input
Extended Keyboard