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A331014
Number of unlabeled bicolored bipartite graphs on 2n nodes having n nodes of each color with no edges between vertices of the same color and edges having three colors and allowing the node color classes to be interchanged. Edge colors are swappable (permuted by the symmetric group).
1
1, 6, 84, 7946, 5413511, 25231086540, 800871112032930, 177544715836044855636, 281653040526999655665449719, 3266495639384107667257990172349726, 282129919925994006382238965837655927175534, 184379837924757642947198903200667422197524750679153
OFFSET
1,2
COMMENTS
Color swaps of the node colors are reflections of the biclique about a vertical axis, with one part on the left and the other on the right. Edge colors are distinct from the two node colors.
REFERENCES
E. Palmer and F. Harary, Graphical Enumeration, Academic Press, 1973.
LINKS
Marko Riedel, Math.StackExchange, Counting bicliques
CROSSREFS
Sequence in context: A244961 A293455 A334516 * A295229 A330849 A245232
KEYWORD
nonn
AUTHOR
Marko Riedel, Jan 06 2020
STATUS
approved