[seqfan] Unlabeled Motzkin numbers - non-intersecting chords on a free circle

David Scambler dscambler at bmm.com
Sat Nov 6 01:21:31 CET 2010


Folk,
If a circle is free to be flipped over (by analogy to free ominos) then there are fewer unique ways to draw non-intersecting chords between equally spaced unlabeled points.

My counts are:

1,1,2,2,4,5,11,16,36,65,150,312,756,1743,4353...

Confirmation would be welcome,
Regards
dave




More information about the SeqFan mailing list