I can't provide a mathematical calculation (you are asking too much LOL). In fact, the multireplicate command is very useful to create e. g. groups of objects (I have a pic in the Bryce gallery (beacon), where I replicated the columns). However, the function is indeed complex. I would recommend to test the function with a simple object before creating something more complex. You have to show and move the origin handle (under Attributes; you can also move the green point manually)and set a rotation angle as well as the number of copies to get an effect that you can see in the pic. You may scale the copies (which is done continuously), but to test the function, I would recommend to start with easy settings (size x,y,z = 100%).