Constant XP Table

Im looking at the gameplay constants pertaining to Hero EXP now and theyre not making any sense to me at all. Could someone tell me how i could change it such that heroes level up every 500 exp? i.e. lvl 2 500 exp, lvl 10 at 5000 exp and lvl 50 at 25000 exp.

I figured out this equasion a while ago, if its wrong its because i was using it for entirely trigger based exp. That and i havent checked it since before TFT came out.

(xz)+((z-1)zy)

x = Constant table
y = Level factor
z = character level

So if my equasion is right set "constant table" = 500 and set "level factor" = 0.