Results 1 to 10 of about 569 (73)
Two examples of Wilf-collapse [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 Two permutation classes, the X-class and subpermutations of the increasing oscillation are shown to exhibit an exponential Wilf-collapse. This means that the number of distinct enumerations of principal subclasses of each of these classes grows much more
Michael Albert +2 more
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Enumerating two permutation classes by the number of cycles [PDF]
Discrete Mathematics & Theoretical Computer Science, 2022 We enumerate permutations in the two permutation classes $\text{Av}_n(312, 4321)$ and $\text{Av}_n(321, 4123)$ by the number of cycles each permutation admits. We also refine this enumeration with respect to several statistics.
Kassie Archer
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Twenty Vertex Model and Domino Tilings of the Aztec Triangle [PDF]
Electronic Journal of Combinatorics, 2021 We show that the number of configurations of the 20 Vertex model on certain domains with domain wall type boundary conditions is equal to the number of domino tilings of Aztec-like triangles, proving a conjecture of the author and Guitter.
P. Francesco
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Enumeration of Stack-Sorting Preimages via a Decomposition Lemma [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 We give three applications of a recently-proven "Decomposition Lemma," which allows one to count preimages of certain sets of permutations under West's stack-sorting map $s$.
Colin Defant
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Enumeration of Dumont permutations avoiding certain four-letter patterns [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 In this paper, we enumerate Dumont permutations of the fourth kind avoiding or containing certain permutations of length 4. We also conjecture a Wilf-equivalence of two 4-letter patterns on Dumont permutations of the first kind.
Alexander Burstein, Opel Jones
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The number of distinct adjacent pairs in geometrically distributed words [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 A sequence of geometric random variables of length $n$ is a sequence of $n$ independent and identically distributed geometric random variables ($\Gamma_1, \Gamma_2, \dots, \Gamma_n$) where $\mathbb{P}(\Gamma_j=i)=pq^{i-1}$ for $1~\leq~j~\leq~n$ with $p+q=
Margaret Archibald +5 more
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Lattice Paths and Pattern-Avoiding Uniquely Sorted Permutations [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 Defant, Engen, and Miller defined a permutation to be uniquely sorted if it has exactly one preimage under West's stack-sorting map. We enumerate classes of uniquely sorted permutations that avoid a pattern of length three and a pattern of length four by
Hanna Mularczyk
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Recent developments in combinatorial aspects of normal ordering
Enumerative Combinatorics and Applications, 2021 In this paper, we report on recent progress concerning combinatorial aspects of normal ordering. After giving a short introduction to the history and motivation of normal ordering, we present some recent developments.
M. Schork
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Certificate complexity and symmetry of nested canalizing functions [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 Boolean nested canalizing functions (NCFs) have important applications in molecular regulatory networks, engineering and computer science. In this paper, we study their certificate complexity.
Yuan Li, Frank Ingram, Huaming Zhang
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α-Completely Regular and Almost α-Completely Regular Spaces
Mathematical Problems in Engineering, 2022 This work is aimed at studying some of the characterizations of α-completely regular and almost α-completely regular spaces through the new concept of α-zero sets and α-continuous functions.
A. Azzam, A. Nasef
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