Results 61 to 70 of about 143 (87)
Convexity of tableau sets for type A Demazure characters (key polynomials), parabolic Catalan numbers [PDF]
Discrete Mathematics & Theoretical Computer Science, 2018 This is the first of three papers that develop structures which are counted by a "parabolic" generalization of Catalan numbers. Fix a subset R of {1,..,n-1}. Consider the ordered partitions of {1,..,n} whose block sizes are determined by R. These are the
Robert A. Proctor, Matthew J. Willis
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Classical pattern distributions in $\mathcal{S}_{n}(132)$ and $\mathcal{S}_{n}(123)$ [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 Classical pattern avoidance and occurrence are well studied in the symmetric group $\mathcal{S}_{n}$. In this paper, we provide explicit recurrence relations to the generating functions counting the number of classical pattern occurrence in the set of ...
Dun Qiu, Jeffrey Remmel
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Consecutive Patterns in Inversion Sequences [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 An inversion sequence of length $n$ is an integer sequence $e=e_{1}e_{2}\dots e_{n}$ such that $0\leq e_{i}
Juan S. Auli, Sergi Elizalde
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Key-avoidance for alternating sign matrices [PDF]
Discrete Mathematics & Theoretical Computer ScienceWe initiate a systematic study of key-avoidance on alternating sign matrices (ASMs) defined via pattern-avoidance on an associated permutation called the \emph{key} of an ASM.
Mathilde Bouvel +2 more
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Two-sided permutation statistics via symmetric functions
Forum of Mathematics, SigmaGiven a permutation statistic $\operatorname {\mathrm {st}}$ , define its inverse statistic $\operatorname {\mathrm {ist}}$ by . We give a general approach, based on the theory of symmetric functions, for finding the joint distribution of
Ira M. Gessel, Yan Zhuang
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K-Orbit closures and Hessenberg varieties
Forum of Mathematics, SigmaThis article explores the relationship between Hessenberg varieties associated with semisimple operators with two eigenvalues and orbit closures of a spherical subgroup of the general linear group.
Mahir Bilen Can +3 more
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Pattern Avoidance in Weak Ascent Sequences [PDF]
Discrete Mathematics & Theoretical Computer ScienceIn this paper, we study pattern avoidance in weak ascent sequences, giving some results for patterns of length 3. This is an analogous study to one given by Duncan and Steingr\'imsson (2011) for ascent sequences. More precisely, we provide systematically
Beáta Bényi +2 more
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On the $\operatorname{rix}$ statistic and valley-hopping [PDF]
Discrete Mathematics & Theoretical Computer ScienceThis paper studies the relationship between the modified Foata$\unicode{x2013}$Strehl action (a.k.a. valley-hopping)$\unicode{x2014}$a group action on permutations used to demonstrate the $\gamma$-positivity of the Eulerian polynomials$\unicode{x2014 ...
Nadia Lafrenière, Yan Zhuang
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Interval and $\ell$-interval Rational Parking Functions [PDF]
Discrete Mathematics & Theoretical Computer ScienceInterval parking functions are a generalization of parking functions in which cars have an interval preference for their parking. We generalize this definition to parking functions with $n$ cars and $m\geq n$ parking spots, which we call interval ...
Tomás Aguilar-Fraga +14 more
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Finite automata, probabilistic method, and occurrence enumeration of a pattern in words and permutations. [PDF]
SIAM J Discret Math, 2020 Mansour T, Rastegar R, Roitershtein A.
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