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Chromatic classes of 2-connected $$(n,n+3)$$-graphs with at least two triangles. (English) Zbl 0796.05033
Two graphs $$G$$ and $$H$$ are said to be chromatically equivalent if their chromatic polynomials are the same. A graph $$G$$ is said to be chromatically unique if every graph chromatically equivalent to $$G$$ is isomorphic to $$G$$. Let $$C$$ denote the class of all 2-connected graphs of order $$n$$ and size $$n+3$$ having at least two 3-cycles. In this paper all equivalence classes in $$C$$ under the equivalence relation of chromatic equivalence are determined; the structure of the graphs in each class is characterized; new families of chromatically equivalent and chromatically unique graphs are produced.

##### MSC:
 05C15 Coloring of graphs and hypergraphs 05C38 Paths and cycles
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##### References:
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