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, 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

Table of n, a(n) for n=1..12.

Marko Riedel, Math.StackExchange, Counting bicliques

Crossrefs

Cf. A007139, A331013.

Sequence in context: A244961 A293455 A334516 * A295229 A330849 A245232

Adjacent sequences: A331011 A331012 A331013 * A331015 A331016 A331017

Keyword

nonn

Author

Marko Riedel, Jan 06 2020

Status

approved