A note on the chromaticity of some 2-connected (n,n+3)-graphs

Let P(G,λ) denote the chromatic polynomial of a graph G. A graph G is chromatically unique if G≅H for any graph H such that P(H,λ)=P(G,λ). This note corrects an error in the proof of the chromatic uniqueness of certain 2-connected graphs with n vertices and n+3 edges.