(c1+c2+c3+c7)*(n-1)+c_4*((1/2)*n*(n-1)+n-1)+(c5+c6)*((1/2)*n*(n-1))

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.