note Adam You win on the efficiency test too. with n = 100 we are roughly the same time, but as n gets large I get bogged down somewhere. I'm running a test with n = 1000000 on my dual proc, which has been hung for about five minutes now. But based on the out put I've already seen for smaller n's, I suspect that you will slaughter me time wise.<p> I don't understand why yours is faster because you use two for loops and I use a while loop the second time, dropping the overhead of making the temp array that foreach generates. Now I'm curious about the efficiencies of the two looping mechanisms... 20633 20694