|
|
A331013
|
|
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 two colors and allowing the node color classes to be interchanged. Edge colors are swappable (permuted by the symmetric group).
|
|
2
|
|
|
1, 4, 13, 104, 1507, 64203, 8426875, 3671999389, 5366787092478, 26433809041087192, 441089058039611200394, 25113998661290096278734134, 4918524299370332513672165781112, 3340919807757080784843712707230030713, 7933888983010307508332924524920878232000997, 66370395190630232518212377765981306426650525779505
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
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
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|