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((3+5(j-1))/2^j, {j, 1, 1000})
sum((3+5(j-1))/2^j, {j, 1, 1000})
Natural Language
Math Input
Extended Keyboard