Ars Combinatoria

ISSN 0381-7032 (print), 2817-5204 (online)

Ars Combinatoria is the oldest Canadian journal of combinatorics, established in 1976, dedicated to advancing combinatorial mathematics through the publication of high-quality, peer-reviewed research papers. Over the decades, it has built a strong international reputation and continues to serve as a leading platform for significant contributions to the field.
Open Access:  The journal follows the Diamond Open Access model—completely free for both authors and readers, with no article processing charges (APCs). 
Publication Frequency: From 2024 onward, Ars Combinatoria publishes four issues annually—in March, June, September, and December.
Scope: Publishes research in all areas of combinatorics, including graph theory, design theory, enumeration, algebraic combinatorics, combinatorial optimization and related fields.
Indexing & Abstracting:  Indexed in MathSciNet, Zentralblatt MATH, and EBSCO, ensuring wide visibility and scholarly reach.
Rapid Publication: Submissions are processed efficiently, with accepted papers published promptly in the next available issue.
Print & Online Editions: Issues are available in both print and online formats to serve a broad readership.

Mingjin Wang1
1DEPARTMENT OF APPLIED MATHEMATICS, CHANGZHOU UNIVERSITY CHANGZHOU, JIANGSU, 213164, P.R CHINA
Abstract:

In this paper, we use the \(q\)-difference operator and the Andrews-Askey integral to give a transformation for the Al-Salam-Carlitz polynomials. As applications, we obtain an expansion of the Carlitz identity and some other identities for Al-Salam-Carlitz
polynomials .

Dorota Brod1, Krzysztof Piejko1, Iwona Wloch1
1Rzeszow University of Technology Faculty of Mathematics and Applied Physics al. Powstancow Warszawy 12, 35-959 Rzeszow, Poland
Abstract:

In this paper we define new generalizations of the Lucas numbers,which also generalize the Perrin numbers. This generalization is based on the concept of \(k\)-distance Fibonacci numbers. We give in-terpretations of these numbers with respect to special decompositions and coverings, also in graphs. Moreover, we show some identities for these numbers, which often generalize known classical relations for the Lucas numbers and the Perrin numbers. We give an application of the distance Fibonacci numbers for building the Pascal’s triangle.

Shi-Qin Liu1
1Department Mathematics and Computer, Hengshui College, Hebei 053000, P.R. China
Abstract:

This paper introduces the new notions of \(\delta-\alpha-\)open sets and the \(\delta-\alpha-\)continuous functions in the topological spaces and investigates some of their properties.

Jiangtao Peng1, Yuanlin Li2
1COLLEGE OF SCIENCE, CIVIL AVIATION UNIVERSITY OF CHINA, TIANJIN 300300, P.R. CHINA
2 DEPARTMENT OF MATHEMATICS, Brock UNIVERSITY, ST. CATHARINES, ONTARIO, Canada L2S 3A1
Abstract:

Let \(G\) be a finite cyclic group. Every sequence \(S\) of length \(l\) over \(G\) can be written in the form \(S = (n_1g) \cdots (n_lg)\), where \(g \in G\) and \(n_1, \ldots, n_l \in [1, \text{ord}(g)]\), and the \({index}\) \(\text{ind}(S)\) of \(S\) is defined to be the minimum of \((n_1 + \cdots + n_l)/\text{ord}(g)\) over all possible \(g \in G\) such that \(\langle g \rangle = G\). In this paper, we determine the index of any minimal zero-sum sequence \(S\) of length \(5\) when \(G = \langle g \rangle\) is a cyclic group of a prime order and \(S\) has the form \(S = g^2{(n_2g)}(n_3g){(n_4)}\). It is shown that if \(G = \langle g \rangle\) is a cyclic group of prime order \(p \geq 31\), then every minimal zero-sum sequence \(S\) of the above-mentioned form has index \(1\), except in the case that \(S = g^2(\frac{p-1}{2}g)(\frac{p+3}{2}g)((p-3)g)\).

Gui-Xian Tian1, Ting-Zhu Huang2, Shu-Yu Cui3
1College of Mathematics, Physics and Information Engineering, Zhejiang Normal University, Jinhua, Zhejiang, 321004, P.R. China
2School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan, 611781, P.R. China
3Xingzhi College, Zhejiang Normal University, Jinhua, Zhejiang, 21004, P.R. China
Abstract:

The paper presents two sharp upper bounds for the largest Laplacian eigenvalue of mixed graphs in terms of the degrees and the average \(2\)-degrees, which improve and generalize the main results of Zhang and Li [Linear Algebra Appl.\(353(2002)11-20]\),Pan (Linear Algebra Appl.\(355(2002)287-295]\),respectively. Moreover, we also characterize some extreme graphs which attain these upper bounds. In last, some examples show that our bounds are improvement on some known bounds in some cases.

Fen Luo1, Jianming Zhan1
1Department of Mathematics, Hubet University for Nationalities, Enshi, Hubei Province 445000, China
Abstract:

Cagman \(et\; al\). introduced the concept of a fuzzy parameterized fuzzy soft set(briefly, \(FPFS)\) which is an extension of a fuzzy set and a soft set. In this paper, we introduce the concepts of \(FPFS\) filters and \(FPFS\) implicative filters of lattice implication algebras and obtain some related results. Finally, we define the concept of \(FPFS\)-aggregation operator of lattice implication algebras.

Minko Markov1, Tzvetalin S.Vassilev2, Krassimir Manev3
1Department of Computing Systems, Faculty of Mathematics and Informatics, “St. Kliment Ohridski” University of Sofia, 5 J. Bourchier Blvd, P.O. Box 48, BG-1164 Sofia, Bulgaria.
2Department of Computer Science and Mathematics, Nipissing University, 100 College Drive, Box 5002 North Bay, Ontario PIB 8L7, Canada.
3Department of Computing Systems, Faculty of Mathematics and Informatics, “St. Kliment Obridski” University of Sofia, 5 J. Bourchier Blvd, P.O. Box 48, BG-1164 Sofia, Bulgaria.
Abstract:

We propose a practical linear time algorithm for the LONGEST PATH problem on \(2\)-trees.

Qinglun Yan1, Yingmei Zhang1, Xiaona Fan1
1College of Science, Nanjing University of Posts and Telecommunications, Nanjing 210046, P. R. China
Abstract:

By means of a \(q\)-binomial identity, we give two generalizations of Prodinger’s formula, which is equivalent to the famous Dilcher’s formula.

Jennie C.Hansen1, Jerzy Jaworski2
1Actuarial Mathematics and Statistics Department and The Maxwell Institute for Mathematical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
2Faculty of Mathematics and Computer Science, Adam Mickiewicz University, Umul- towska 87, 61-614 Poznai, Poland
Abstract:

In this paper, we consider a random mapping \(\hat{T}_{n,\theta}\) of the finite set \(\{1,2,\ldots,n\}\) into itself, for which the digraph representation \(\hat{G}_{n,\theta}\) is constructed by: (1) selecting a random number \(\hat{L}_n\) of cyclic vertices, (2) constructing a uniform random forest of size \(n\) with the selected cyclic vertices as roots, and (3) forming `cycles’ of trees by applying to the selected cyclic vertices a random permutation with cycle structure given by the Ewens sampling formula with parameter \(\theta\). We investigate \(\hat{k}_{n,\theta}\), the size of a `typical’ component of \(\hat{G}_{n,\theta}\), and we obtain the asymptotic distribution of \(\hat{k}_{n,\theta}\) conditioned on \(\hat{L}_n = m(n)\). As an application of our results, we show in Section 3 that provided \(\hat{L}_n\) is of order much larger than \(\sqrt{n}\), then the joint distribution of the normalized order statistics of the component sizes of \(G_{n,\theta}\) converges to the Poisson-Dirichlet \((\theta)\) distribution as \(n \to \infty\).

Dae San Kim1, Taekyun Kim2, Sang-Hun Lee3, Seog-Hoon Rim4
1Department of Mathematics, Sogang University, Seoul 121-742, S. Korea
2Department of Mathematics, Kwangwoon University, Seoul 139-701, S.Korea
3Division of Genera Education, Kwangwoon University, Seoul 139-701, S.Korea
4Department of Mathematics Education, Kyungpook National University, Taegu 702-701, S. Korea
Abstract:

In this paper, we study some properties of Euler polynomials arising from umbral calculus. Finally, we give some interesting identities of Euler polynomials using our results. Recently, D. S. Kim and T. Kim have studied some identities of Frobenius-Euler polynomials arising from umbral calculus \((see[6])\).