PHP Math Question

I'm am completely stumped on a seemingly simple math formula I need to find a way to map a set of numbers up to 4 (e.g. 1,2,3,4 or 1,2) to any number in a range of up to 10,000 (ideally, unlimited). Such that, (e.g. 1,2,3,4) 1 is to 1 2 is to 2 3 is to 3 4 is to 4 5 is to 1 6 is to 2 7 is to 3 8 is to 4 9 is to 1 10 is to 2 11 is to 3 12 is to 4 13 is to 1 14 is to 2 15 is to 3 16 is to 4 And so on... Is anyone good at math, that can throw me a bone? Thanks y'all, Mike D .................................... Mike Dunlop AWN, Inc. // www.awn.com [ e ] webmaster@awn.com [ p ] 323.606.4237