Pattern avoidance in partial permutations
Claesson, A. and Jelinek, V. and Jelinkova, E. and Kitaev, S. (2011) Pattern avoidance in partial permutations. The Electronic Journal of Combinatorics, 18 (1). ISSN 10778926

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Abstract
Motivated by the concept of partial words, we introduce an analogous concept of partial permutations. A partial permutation of length n with k holes is a sequence of symbols $\pi = \pi_1\pi_2 ... \pi_n$ in which each of the symbols from the set {1,2,...,nk} appears exactly once, while the remaining k symbols of $\pi$ are "holes". We introduce patternavoidance in partial permutations and prove that most of the previous results on Wilf equivalence of permutation patterns can be extended to partial permutations with an arbitrary number of holes. We also show that Baxter permutations of a given length k correspond to a Wilftype equivalence class with respect to partial permutations with (k2) holes. Lastly, we enumerate the partial permutations of length n with k holes avoiding a given pattern of length at most four, for each n >= k >= 1.
Item type:  Article 

ID code:  40421 
Keywords:  Wilfequivalence, generating function, pattern avoidance, partial permutation, StanleyWilf conjecture, bijection, partial words, fillings, Baxter permutation, Electronic computers. Computer science, Computational Theory and Mathematics, Geometry and Topology, Theoretical Computer Science 
Subjects:  Science > Mathematics > Electronic computers. Computer science 
Department:  Faculty of Science > Computer and Information Sciences 
Depositing user:  Pure Administrator 
Date Deposited:  17 Jul 2012 11:54 
Last modified:  05 May 2016 08:15 
Related URLs:  
URI:  http://strathprints.strath.ac.uk/id/eprint/40421 