Results 21 to 30 of about 145 (113)

Enumerating two permutation classes by the number of cycles [PDF]

open access: yesDiscrete 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
doaj   +1 more source

Negative moments of orthogonal polynomials

open access: yesForum of Mathematics, Sigma, 2023
If a sequence indexed by nonnegative integers satisfies a linear recurrence without constant terms, one can extend the indices of the sequence to negative integers using the recurrence.
Jihyeug Jang   +4 more
doaj   +1 more source

Refined ratio monotonicity of the coordinator polynomials of the root lattice of type Bn

open access: yesOpen Mathematics, 2023
Ratio monotonicity, a property stronger than both log-concavity and the spiral property, describes the behavior of the coefficients of many classical polynomials.
Su Xun-Tuan, Sun Fan-Bo
doaj   +1 more source

A combinatorial model for the transition matrix between the Specht and $\operatorname {SL}_2$ -web bases

open access: yesForum of Mathematics, Sigma, 2023
We introduce a new class of permutations, called web permutations. Using these permutations, we provide a combinatorial interpretation for entries of the transition matrix between the Specht and $\operatorname {SL}_2$ -web bases of the irreducible
Byung-Hak Hwang   +2 more
doaj   +1 more source

In vitro antimicrobial activity of a gel containing antimicrobial peptide AMP2041, chlorhexidine digluconate and Tris‐EDTA on clinical isolates of Pseudomonas aeruginosa from canine otitis

open access: yesVeterinary Dermatology, Volume 27, Issue 5, Page 391-e98, October 2016., 2016
Background– Pseudomonas aeruginosa (PA) may cause suppurative otitis externa with severe inflammation and ulceration in dogs. Multidrug resistance is commonly reported for this organism, creating a difficult therapeutic challenge. Objective– The aim of this study was to evaluate the in vitro antimicrobial activity of a gel containing 0.5 µg/mL of ...
Giovanni Ghibaudo   +6 more
wiley   +1 more source

Determinantal generating functions of colored spanning forests

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 6, Page 273-283, 2004., 2004
The color type of a spanning forest of a graph with colored edges is defined and, subsequently, it is proved that the generating function of such spanning forests is obtained as the formal expansion of a certain determinant. An analogous determinantal expansion yields the generating function of all spanning forests of a given color type that contain a ...
Gregory M. Constantine, Marius G. Buliga
wiley   +1 more source

Counting occurrences of 132 in an even permutation

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 25, Page 1329-1341, 2004., 2004
We study the generating function for the number of even (or odd) permutations on n letters containing exactly r ≥ 0 occurrences of a 132 pattern. It is shown that finding this function for a given r amounts to a routine check of all permutations in 𝔖2r.
Toufik Mansour
wiley   +1 more source

MacMahon’s statistics on higher-dimensional partitions

open access: yesForum of Mathematics, Sigma, 2023
We study some combinatorial properties of higher-dimensional partitions which generalize plane partitions. We present a natural bijection between d-dimensional partitions and d-dimensional arrays of nonnegative integers.
Alimzhan Amanov, Damir Yeliussizov
doaj   +1 more source

First hitting times of simple random walks on graphs with congestion points

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 30, Page 1911-1922, 2003., 2003
We derive the explicit formulas of the probability generating functions of the first hitting times of simple random walks on graphs with congestion points using group representations.
Mihyun Kang
wiley   +1 more source

The log-concavity of the q-derangement numbers of type B

open access: yesOpen Mathematics, 2018
Recently, Chen and Xia proved that for n ≥ 6, the q-derangement numbers Dn(q) are log-concave except for the last term when n is even. In this paper, employing a recurrence relation for DnB(q) $\begin{array}{} \displaystyle D^B_n(q) \end{array ...
Liu Eric H., Du Wenjing
doaj   +1 more source

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