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A Note on Counting Homomorphisms of Paths
Authors:Roger B Eggleton  Michał Morayne
Institution:1. Department of Mathematics, Illinois State University, Normal, IL, 61790, USA
2. Institute of Mathematics and Computer Science, Wroc?aw University of Technology, Wybrze?e Wyspiańskiego 27, 50-370, Wroc?aw, Poland
Abstract:We obtain two identities and an explicit formula for the number of homomorphisms of a finite path into a finite path. For the number of endomorphisms of a finite path these give over-count and under-count identities yielding the closed-form formulae of Myers. We also derive finite Laurent series as generating functions which count homomorphisms of a finite path into any path, finite or infinite.
Keywords:
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