> You've probably noticed that all the 2-panel cards are a distinct > pair, and all possible pairs occur once, both in the horizontal > and in the vertical divides. In fact, such pairings always > produce a triangular number, as in standard dominoes, hence 10 > cards: 1/2, 1/3, 1/4, 1/5, 2/3, 2/4, 2/5, 3/4, 3/5, 4/5. > > Isn't this just the greatest fun? You can implicitly teach group > theory, systems thinking, combinatorics, and organizing by matching elements. Wow. Somebody is a math geek... Good on ya. Cool analysis of the patterns. Thanks for doing the math so the rest of us didn't have to. :)