Excel Fill Formula Down

Hi,

So I have some formulas that are essentially adding up in increments of 1. So for example

=18.02*1

=18.02*2

=18.02*3

=18.02*4

and I've manually done up to 10, but want Excel to keep calculating it once I've highlighted it and dragging down, but its just repeating the sequence. How can I get it to do what I want it to do?

Thanks,

Bobby