On Feb 21, 2007, at 4:50 AM, rretzbach / googlemail.com wrote: > So far the only perfect "algo" that came to my mind was to create > all possible books and chose one randomly. You can create a lot less than "all possible books" if you think in terms of patterns, and still be able to create all of the combinations. Think about what moves around in the tickets/books besides the numbers. James Edward Gray II