Re: > > How about this? > 1 > 11 > 21 > 1211 > 111221 > 312211 For a good description, see: http://www2.edc.org/makingmath/handbook/Teacher/IntroductoryExplorations/IntroductoryExplorations.asp (long URL) Stan Sieler [log in to unmask] www.allegro.com/sieler/wanted/index.html www.allegro.com/sieler