Matching Forcing Polynomials of Constructable Hexagonal Systems

Abstract

Harary et al. put forward the concept on the minimum cardinality over all subsets of perfect matching M that are not included by any other ones, to be the forcing number for M. A counting polynomial for perfect matchings possessing the same forcing number was introduced by Zhang et al., using the name `forcing polynomial'. This research deduces recurrence formulas of forcing polynomials for monotonic constructable hexagonal systems and constructable hexagonal systems with one turning. From them, a characterization of continuity of forcing spectrum for hexagonal systems with forcing edges can be derived.