What are the chances of four of X (variable) rolled six-sided dice producing a result of “5” or “6” in one roll?

4 dice = 1.2%

5 dice = ???

6 dice = ???

etc.

I know that each die has a 1 out of 3 (or 1/3, or 33.4%) chance of producing the desired result of 5 or 6 (also called a "hit"). I know that the chances of all four dice of a four-die roll "hitting" is equal to the chance of one of them hitting times the chance of each other one hitting, i.e.

(1/3)*(1/3)*(1/3)*(1/3)

Thank you for your time and your help!