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.
S=1/2*1/6*(t*(t+1))*(2t+1-3)=1/6*(t*(t+1)*(t-1))=(t^3-t)/6
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random