Name for a number generator method

Suppose I am developing an algorithm that needs a number that must be between to numbers and for that values it must always be the same number. I moved that calculation to a new method because I use it repeated times.

My friend proposed me to call it "randomBetween(min, max)" but I argue that is not correct because it always return the same value if I send the same arguments, so it isn't random.

Am I wrong?

Thanks