A Note on Counting Homomorphisms of Paths
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...
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Published in | Graphs and combinatorics Vol. 30; no. 1; pp. 159 - 170 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Tokyo
Springer Japan
2014
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | 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. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0911-0119 1435-5914 |
DOI: | 10.1007/s00373-012-1261-0 |