Results 11 to 20 of about 158 (109)
The Hurwitz action in complex reflection groups [PDF]
, 2022 We enumerate Hurwitz orbits of shortest reflection factorizations of an arbitrary element in the infinite family \(G(m, p, n)\) of complex reflection groups.
Lewis, Joel Brewster, Wang, Jiayuan
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The homogenized Linial arrangement and Genocchi numbers [PDF]
, 2022 We study the intersection lattice of a hyperplane arrangement recently introduced by Hetyei who showed that the number of regions of the arrangement is a median Genocchi number.
Wachs, Michelle L., +3 more
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The combinatorics of a tree-like functional equation for connected chord diagrams [PDF]
, 2023 We build on recent work of Yeats, Courtiel, and others involving connected chord diagrams. We first derive from a Hopf-algebraic foundation a class of tree-like functional equations and prove that they are solved by weighted generating functions of two ...
Nabergall, Lukas
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Grass(mannian) trees and forests: Variations of the exponential formula, with applications to the momentum amplituhedron [PDF]
, 2023 The Exponential Formula allows one to enumerate any class of combinatorial objects built by choosing a set of connected components and placing a structure on each connected component which depends only on its size.
Moerman, Robert, Williams, Lauren K.
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Flip-sort and combinatorial aspects of pop-stack sorting [PDF]
Discrete Mathematics & Theoretical Computer Science, 2021 Flip-sort is a natural sorting procedure which raises fascinating combinatorial questions. It finds its roots in the seminal work of Knuth on stack-based sorting algorithms and leads to many links with permutation patterns. We present several structural,
Andrei Asinowski +2 more
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Snow Leopard Permutations and Their Even and Odd Threads [PDF]
Discrete Mathematics & Theoretical Computer Science, 2016 Caffrey, Egge, Michel, Rubin and Ver Steegh recently introduced snow leopard permutations, which are the anti-Baxter permutations that are compatible with the doubly alternating Baxter permutations. Among other things, they showed that these permutations
Eric S. Egge, Kailee Rubin
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Down-step statistics in generalized Dyck paths [PDF]
Discrete Mathematics & Theoretical Computer Science, 2022 The number of down-steps between pairs of up-steps in $k_t$-Dyck paths, a generalization of Dyck paths consisting of steps $\{(1, k), (1, -1)\}$ such that the path stays (weakly) above the line $y=-t$, is studied.
Andrei Asinowski +2 more
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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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Further enumeration results concerning a recent equivalence of restricted inversion sequences [PDF]
Discrete Mathematics & Theoretical Computer Science, 2022 Let asc and desc denote respectively the statistics recording the number of ascents or descents in a sequence having non-negative integer entries.
Toufik Mansour, Mark Shattuck
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