Ok, I don't quite have the fonts I need to show this question, so Im going to describe it. Basically, in my math 100 course we're on the summation, products and reimann sums unit. I'm having trouble with the product sums (which look like sigma notation, but with a pi symbol in place of sigma). I'll use 2 number signs instead of the pi thingy because I dont have a font with that symbol.

What is:

98

## 2^i

i=-1

Hopefully that makes sense and hopefully someone can help. Thank you