Question about the movie Inception (spoiler alert)?

It was explained that 5 minutes of dreaming in reality / level 0 corresponds to 1 hour in the subconscious, and the deeper you descend into the person's subconscious, the more the effect is multiplied.

My question is this: Was it stated in the movie by how much the effect was multiplied as you entered deeper levels of the subconscious?

Was it time spent dreaming (in reality / level 0), multiplied by 12 to the power of the level of subconscious, which equals the amount of time experienced in the subconscious?

For example, if T=Time spent in a dream state in reality / level 0, the 2nd level would be T*12^2, and the 3rd level would be T*12^3 (since five minutes spent dreaming in level 0 is 1/12th the amount of time experienced in level 1). Is that how it worked?