Number of primitive sorting networks on n elements; also number of rhombic tilings of 2n-gon.
1, 1, 2, 8, 62, 908, 24698, 1232944, 112018190, 18410581880, 5449192389984
1 seqfan posts
Tue Sep 8 13:36:46 CEST 2009 [seqfan] Re: Rhombic dissections of regular polygons