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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.
1
0, 0, 1, 2, 3, 7, 22, 57, 174, 554, 1848, 6291, 22052, 78361, 282420
OFFSET
4,4
COMMENTS
Also the number of isomorphism classes of homologically trivial basic nets on RP^2 with n-1 nodes and n faces.
Also the number of isomorphism classes of simple quadrangulations of the sphere of minimum degree 3 with 2n nodes and 2n-2 faces which admit an orientation reversing involution without fix nodes and fix edges such that the bipartite coloring is preserved under the involution.
CROSSREFS
Sequence in context: A155745 A067738 A296287 * A053966 A010738 A114599
KEYWORD
nonn,more
AUTHOR
Stepan Orevkov, Aug 30 2013
STATUS
approved