"tails" seems to be the key. I haven't thought of this before.

Thanks for pointing me in the right direction, guys.

For a more "interesting" solution: http://blog.sigfpe.com/2006/12/evaluating-cellular-automata-is.html I believe you can adapt his 'rule' function to your problem. It's probably overkill, but good learning material =) Have fun! -- Ariel J. Birnbaum