n is just the principle quantum number and doesn't affect the magnetic moment.

The l is the magnetic quantum number. It can be oriented up or down (+3 to -3) or at a slight angle, but always in units of 1.

So there are 7 quantum states:

l = -3, -2, -1, 0, 1, 2, 3.

From -3 to +3 inclusive, in integer steps.

I assume you're not including electron spin, since that would make it go from -3.5 to +3.5!