Results 21 to 30 of about 302 (115)
Enumeration of Stack-Sorting Preimages via a Decomposition Lemma [PDF]
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
doaj +1 more source
Enumeration of Dumont permutations avoiding certain four-letter patterns [PDF]
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
doaj +1 more source
The number of distinct adjacent pairs in geometrically distributed words [PDF]
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
doaj +1 more source
On sums with generalized harmonic, hyperharmonic and special numbers
In this paper, we establish interesting sums including generalized harmonic numbers and special numbers by using generating functions of these numbers and some combinatorial identities.
Ö. Duran, N. Ömür, S. Koparal
semanticscholar +1 more source
Remixed Eulerian numbers are a polynomial q-deformation of Postnikov’s mixed Eulerian numbers. They arose naturally in previous work by the authors concerning the permutahedral variety and subsume well-known families of polynomials such as q-binomial ...
Philippe Nadeau, Vasu Tewari
doaj +1 more source
Negative moments of orthogonal polynomials
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
Deepest Nodes in Marked Ordered Trees
A variation of ordered trees, where each rightmost edge might be marked or not, if it does not lead to an endnode, is investigated. These marked ordered trees were introduced by E. Deutsch et al. to model skew Dyck paths.
Prodinger Helmut
doaj +1 more source
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
Lattice Paths and Pattern-Avoiding Uniquely Sorted Permutations [PDF]
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
doaj +1 more source
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