Results 31 to 40 of about 122,748 (264)
European Journal of Combinatorics, 2001 Recently, Babson and Steingrimsson have introduced generalised permutation patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. We consider pattern avoidance for such patterns, and give a complete solution for the number of permutations avoiding any single pattern of length three with exactly ...
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Pattern Avoidance by Even Permutations [PDF]
The Electronic Journal of Combinatorics, 2011 We study questions of even-Wilf-equivalence, the analogue of Wilf-equivalence when attention is restricted to pattern avoidance by permutations in the alternating group. Although some Wilf-equivalence results break when considering even-Wilf-equivalence analogues, we prove that other Wilf-equivalence results continue to hold in the even-Wilf ...
Andrew Baxter, Aaron D. Jaggard
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Pattern Avoidance Classes and Subpermutations [PDF]
The Electronic Journal of Combinatorics, 2005 Pattern avoidance classes of permutations that cannot be expressed as unions of proper subclasses can be described as the set of subpermutations of a single bijection. In the case that this bijection is a permutation of the natural numbers a structure theorem is given.
Mike D. Atkinson +2 more
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Permutation Pattern matching in (213, 231)-avoiding permutations [PDF]
Discrete Mathematics & Theoretical Computer Science, 2017 Given permutations σ of size k and π of size n with k < n, the permutation pattern matching problem is to decide whether σ occurs in π as an order-isomorphic subsequence.
Both Neou +2 more
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Random Structures & AlgorithmsAbstract The theory of limits of permutations leads to limit objects called permutons, which are certain Borel measures on the unit square. We prove that permutons avoiding a given permutation of order have a particularly simple structure.
Frederik Garbe +3 more
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Pattern avoidance of generalized permutations [PDF]
Advances in Applied Mathematics, 2019 In this paper, we study pattern avoidances of generalized permutations and show that the number of all generalized permutations avoiding $π$ is independent of the choice of $π\in S_3$, which extends the classic results on permutations avoiding $π\in S_3$.
Zhousheng Mei, Suijie Wang
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On avoidance of patterns of the form σ-τ by words over a finite alphabet [PDF]
Discrete Mathematics & Theoretical Computer Science, 2015 Vincular or dashed patterns resemble classical patterns except that some of the letters within an occurrence are required to be adjacent. We prove several infinite families of Wilf-equivalences for $k$-ary words involving vincular patterns containing a ...
Toufik Mansour, Mark Shattuck
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Pediatric Blood &Cancer, EarlyView.ABSTRACT Pediatric gastroenteropancreatic neuroendocrine neoplasms (GEP‐NENs) are extremely rare and clinically heterogeneous. Management has largely been extrapolated from adult practice. This European Standard Clinical Practice Guideline (ESCP), developed by the EXPeRT network in collaboration with adult NEN experts, provides (adult) evidence ...
Michaela Kuhlen +23 more
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Permutations Avoiding Arithmetic Patterns [PDF]
The Electronic Journal of Combinatorics, 2004 A permutation $\pi$ of an abelian group $G$ (that is, a bijection from $G$ to itself) will be said to avoid arithmetic progressions if there does not exist any triple $(a,b,c)$ of elements of $G$, not all equal, such that $c-b=b-a$ and $\pi(c)-\pi(b)=\pi(b)- \pi(a)$. The basic question is, which abelian groups possess such a permutation?
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Wilf classification of triples of 4-letter patterns II [PDF]
Discrete Mathematics & Theoretical Computer Science, 2017 this is the second part of a complete paper in arXiv, see 1605 ...
David Callan +2 more
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