Rational to other form



I'm looking to display answers in a pseudo-'prime factors' type of form eg
I would like 2^n/4 to be coerced into 2^(n-2) for display.
Factor(2^n/4) with factorflag true gives me 2^n/2^2 , is there a way of
getting from there to 2^(n-2) ?
Also 2^n*3^m/6 to go to 2^(n-1)*3^(m-1)  etc.

Regards
Nigel