Having trouble with basic code

Hi

I have just started using logical operators and require some guidance. Basically Im trying to generate some values, not in an array though just variables.

This is basically what Im trying to do

 
a=3
_global.Y1=2;
_global.Y2=4;
_global.Y3=6;
for(i=0;i<=a;i++) {
x*=(some formula)*Y*
}
 

Then what I want to happen is the following calculations to take place and variable created;
x1=(some formula)*Y1
x2=(some formula)*Y2
x3=(some formula)*Y3

Can anyone provide assistance on my problem Im not sure where to start.

Thanks