Maximum Number of Internal Vertices, and Extremal Single Coronoids

1 Maximum Number of Internal Vertices, and Extremal Single Coronoids 

An extremal single coronoid (cf. Par. 3.3.4, especially Definition 3.4), A, is defined by having the maximum number of internal vertices (n ) for a given number of hexagons (h) = 

A coronoid A has a naphthalene hole in other words, it is naphthalenic (cf. Definition 3.3 in Par. 3.3.3, and Observation 1 of Par. 3.6.1). Furthermore, any A is a perfect extremal coronoid it is a perforated extremal benzenoid (cf. Definition 3.5). In this connection, notice the sign of equality in eqn. (21), in contrast to the form of eqn. (3.44). The above properties were used in the derivation of (21). 

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