C#

(n)_k = n! / (n− k)!

On the other hand, I think this guy has done exactly what you want:

http://www.cut-the-knot.com/do_you_know/AllPerm.shtml[^]

Edit:
An even better site is this one:

http://mathforum.org/dr.math/faq/faq.comb.perm.html[^]

David Stone

It seemed similar to someone saying, "Would you like to meet my knife collection?"
Ryan Johnston on Elaine's sig

n=3;
s1 = "A";
s2 = "B";
s3 = "C";

print s1,s2,s3

for (i=0;i<n-1;i++)
{
// shift left
c = s1;
s1 = s2;
s2 = s3;
s3 = c;

print s1,s2,s3
}

// permute two last letters
c = s2;
s2 = s3;
s3 = c;

print s1,s2,s3

for (i=0;i<n-1;i++)
{
// shift left
c = s1;
s1 = s2;
s2 = s3;
s3 = c;
print s1,s2,s3
}

class Perm
{
  public void swap (ref int a, ref int b)
  {
    int temp = a;
    a = b;
    b = temp;
  } 

  public void perm (int []list, int k)
  {
    int m = list.Length - 1;
    int i;
    if (k == m)
    { 
      for (i = 0; i <= m; i++) Console.Write (list [i]);
      Console.WriteLine (" ");
    }
    else
      for (i = k; i <= m; i++)
      {
        swap (ref list [k], ref list [i]);
	perm (list, k+1);
	swap (ref list [k], ref list [i]);
      }
   }
}

class Answer
{
    Answer();

    // obviously you like it when answers are code, not explanations
    // so I answer with code ! :-D
    //

    // the Perm class looks fine for any amount of elements
    // so I guess this ends the discussion...:~ 
    Dispose()
    {
      // this class just got me
    }
}

oCmd = new OleDbCommand(sSQL, oConn);
oCmd.ExecuteNonQuery();

FillUsersList();