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Counting Multiple Cyclic Choices Without Adjacencies

Published online by Cambridge University Press:  20 November 2018

Alice McLeod
Affiliation:
Department of Mathematics and Statistics, McGill University, Montreal, Quebec, H3A2K6
William Moser
Affiliation:
Department of Mathematics and Statistics, McGill University, Montreal, Quebec, H3A2K6
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Abstract

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We give a particularly elementary solution to the following well-known problem. What is the number of $k$-subsets $X\subseteq {{I}_{n}}=\left\{ 1,2,3,\ldots ,n \right\}$ satisfying “no two elements of $X$ are adjacent in the circular display of ${{I}_{n}}$”? Then we investigate a new generalization (multiple cyclic choices without adjacencies) and apply it to enumerating a class of 3-line latin rectangles.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2005

References

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