Results 61 to 70 of about 1,071 (104)
Enumeration of super-strong Wilf equivalence classes of permutations in the generalized factor order [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 Super-strong Wilf equivalence classes of the symmetric group ${\mathcal S}_n$ on $n$ letters, with respect to the generalized factor order, were shown by Hadjiloucas, Michos and Savvidou (2018) to be in bijection with pyramidal sequences of consecutive ...
Ioannis Michos, Christina Savvidou
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Two Vignettes On Full Rook Placements [PDF]
, 2013 Using bijections between pattern-avoiding permutations and certain full rook placements on Ferrers boards, we give short proofs of two enumerative results.
Bloom, Jonathan, Vatter, Vince
core
The permutation class Av(4213,2143) [PDF]
Discrete Mathematics & Theoretical Computer Science, 2017 We determine the structure of permutations avoiding the patterns 4213 and 2143. Each such permutation consists of the skew sum of a sequence of plane trees, together with an increasing sequence of points above and an increasing sequence of points to its ...
David Bevan
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Proofs of Conjectures about Pattern-Avoiding Linear Extensions [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 After fixing a canonical ordering (or labeling) of the elements of a finite poset, one can associate each linear extension of the poset with a permutation.
Colin Defant
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The 26 Wilf-equivalence classes of length five quasi-consecutive patterns [PDF]
Discrete Mathematics & Theoretical Computer Science, 2018 We present two families of Wilf-equivalences for consecutive and quasi-consecutive vincular patterns. These give new proofs of the classification of consecutive patterns of length $4$ and $5$.
Evan Chen, Shyam Narayanan
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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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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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Distribution of sets of descent tops and descent bottoms on restricted permutations [PDF]
Discrete Mathematics & Theoretical Computer ScienceIn this note, we prove some and conjecture other results regarding the distribution of descent top and descent bottom sets on some pattern-avoiding permutations.
Alexander Burstein
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The perimeter of uniform and geometric words: a probabilistic analysis
, 2018 Let a word be a sequence of $n$ i.i.d. integer random variables. The perimeter $P$ of the word is the number of edges of the word, seen as a polyomino. In this paper, we present a probabilistic approach to the computation of the moments of $P$.
Louchard, Guy
core
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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