How do I get more than 1 result from same mathematical equation for different values?

I want to make a Line Chart of A VS B. Now A = 5,10,15,20. And for A = 5, B = 100. This B = 100 was calculated through a very large process where I need to parse a lot of input data. The calculation is pretty large.

Now how to get the other B values from the same equation where only value of A will be changed, so that I can plot the line chart from A & B data.

ex: M = N * 20

N = 1 so M = 20;
N = 2 so M = 40;