A187014 Number of isomorphism classes of simply embedded (i.e., loop-free and without parallel edges bounding a disk) bipartite quadrangulations of RP^2 of minimum degree 3 with n nodes and n-1 faces.
0, 0, 1, 2, 3, 7, 22, 57, 174, 554, 1848, 6291, 22052, 78361, 282420
Offset: 4
Links
- S. Yu. Orevkov, Basic nets in the projective plane
Comments