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A079565 Number of unlabeled and connected graphs on n vertices which are either bipartite or co-bipartite. (G is bipartite iff the vertices can be partitioned into two sets such that all the edges in the graph go from one of these sets to the other. G is cobipartite iff the complement of G is bipartite.). 0
1, 1, 2, 6, 16, 49, 129, 481, 1854 (list; graph; refs; listen; history; text; internal format)



Table of n, a(n) for n=1..9.


Let G be a graph with 5 vertices, 4 of which form a path and the 5th adjacent only to the two vertices in the middle of the path. Then G is not bipartite nor cobipartite because there is a triangle in both G and its complement.


Sequence in context: A214843 A151528 A132803 * A052890 A052814 A192401

Adjacent sequences:  A079562 A079563 A079564 * A079566 A079567 A079568




Jim Nastos, Jan 24 2003



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Last modified December 20 16:24 EST 2014. Contains 252269 sequences.