john n on Sat, 09 Jun 2007 22:16:48 +0200 |
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'necklace'-type classes of combinatorial compositions |
Hello, I am a PARI-GP newbie and wondered whether someone might help me with code for listing the classes of combinatorial compositions of p which contain q elements, and which are equivalent under reflection or cycling. These are closely related to "necklaces". Each equivalence class can be denoted by its lexicographically first element, e.g. when p=10 and q=3, {{1,2,6},{2,6,1},{6,1,2},{6,2,1},{2,1,6},{1,6,2}} can be denoted by {1,2,6}. This is not the same as listing partitions because usually at least some partitions containing the same elements are not equivalent to each other. E.g. when p=10 and q=4, the compositions {1,2,2,5} cannot be transformed into {2,1,2,5} by reflection, cycling, or both, because the instances of '2' are adjacent in one and non-adjacent in the other. A big thank you for any help with this! John N -- View this message in context: http://www.nabble.com/%27necklace%27-type-classes-of-combinatorial-compositions-tf3895323.html#a11043232 Sent from the cr.yp.to - pari-users mailing list archive at Nabble.com.