random permutation

I would like to genrate a random permutation as fast as possible.The problem: The knuth shuffle which is O(n) involves generating n random numbers.Since generating random numbers is quite expensive.I would like to find an O(n) function involving a fixed O(1) amount of random numbers.

I realize that this question has been asked before, but I did not see any relevant answers.

Just to stress a point: I am not looking for anything less than O(n), just an algorithm involving less generation of random numbers.

Thanks