Utilitas Algorithmica (UA)
ISSN: xxxx-xxxx (print)
Utilitas Algorithmica (UA) is a premier, open-access international journal dedicated to advancing algorithmic research and its applications. Launched to drive innovation in computer science, UA publishes high-impact theoretical and experimental papers addressing real-world computational challenges. The journal underscores the vital role of efficient algorithm design in navigating the growing complexity of modern applications. Spanning domains such as parallel computing, computational geometry, artificial intelligence, and data structures, UA is a leading venue for groundbreaking algorithmic studies.
- Research article
- https://doi.org/10.61091/ojac21-02
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 21, 2026
- Pages: 1-21(Paper #2)
- Published Online: 14/03/2026
In this paper, we derive some new combinatorial inequalities by applying well known real analytic results like Hölder’s inequality, Young’s inequality, and Minkowiski’s inequality to the recursively defined sequence \(f_n\) of functions \[\begin{align*} f_0(x) & = \chi_{(-1/2, 1/2)} (x), \nonumber \\ f_{n+1}(x) & = f_n(x+1/2)+ f_n(x-1/2), n \in \mathbb{N}\,\cup \,\{0\}. \end{align*}\] Towards this goal, we derive the closed form of the aforementioned sequence \((f_n)_{n\in \mathbb{N}\,\cup \,\{0\}}\) of functions and show that it is a sequence of simple functions that are linear combinations of characteristic functions of some unit intervals \(I_{n,i},\, i=0,1, …, n\), with values the binomial coefficients \(\binom{n}{i}\) on each unit interval \(I_{n,i}\). We show that \(f_n \in L^p(\mathbb{R})),\, 1\leq p \leq \infty\). Besides applying real analytic methods to formulate some combinatorial inequalities, we also illustrate the application of some combinatorial identities. For example, we use the Vandermonde convolution (or Vandermonde identity), in the study of some properties of the sequence of functions \((f_n)_{n\in\mathbb{ N}\cup \{0\}}\). We show how the \(L^2\) norm of \(f_n\) is related to the Catalan numbers.
- Research article
- https://doi.org/10.61091/ojac21-01
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 21, 2026
- Pages: 1-22(Paper #1)
- Published Online: 14/03/2026
We study Lambert series generating functions associated with arithmetic functions \(f\), defined by
$$L_f(q)=\sum_{n\ge1}\frac{f(n)q^n}{1-q^n}=\sum_{m\ge1}(f*1)(m)q^m.$$
These expansions naturally generate divisor sums through Dirichlet convolution with the constant-one function and provide a useful framework for enumerating ordinary generating functions of many multiplicative functions in number theory. This paper presents an overview of key properties of Lambert series, together with combinatorial generalizations and a compendium of formulas for important special cases. The emphasis is on formal and structural aspects of the sequences generated by these series rather than on analytic questions of convergence. In addition to serving as an introduction, the paper provides a consolidated reference for classical identities, recent connections with partition-generating functions, and other useful Lambert series expansions arising in applications.
- Research article
- https://doi.org/10.61091/ars166-02
- Full Text
- Ars Combinatoria
- Volume 166
- Pages: 15-26
- Published Online: 14/03/2026
We study edge partitions of a bipartite graph into induced-2K2-free bipartite graphs, i.e. into Ferrers (chain) graphs. We define fp(G) as the minimum number of parts in such a partition. We prove general lower and upper bounds in terms of induced matchings and Dilworth widths of neighborhood posets. We compute the parameter exactly for paths and even cycles, and we exhibit separations showing that the induced-matching lower bound and the width upper bound can both be far from tight. We also record a simple host-induced conflict-graph lower bound, present a 0–1 matrix viewpoint, and add some complexity remarks.
- Research article
- https://doi.org/10.61091/jcmcc130-12
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 130
- Pages: 165-185
- Published Online: 07/03/2026
We study the Equivalent Local Sequence Problem (ELSP), which consists in recovering an explicit sequence of local complementations that transforms a graph into a locally equivalent one. Focusing on directed Paley graphs, we establish that local complementations commute and induce a free action of an elementary abelian 2-group. The stabilizer condition is reformulated as a system of convolution equations and analyzed through Fourier techniques over finite fields, leading to a proof of stabilizer triviality. As a consequence, each graph in the orbit admits a unique subset encoding, and ELSP reduces to solving a linear inversion problem over 𝔽2. This characterization completely resolves ELSP for directed Paley graphs, provides a polynomial-time inversion algorithm and highlights structural features that may support future developments in cryptographic frameworks and quantum graph-state models.
- Research article
- https://doi.org/10.61091/jcmcc130-11
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 130
- Pages: 151-164
- Published Online: 07/03/2026
Given a configuration of pebbles on the edges of a connected graph G, an edge pebbling move is defined as the removal of two pebbles off an edge and placing one on an adjacent edge. The domination cover edge pebbling number of a graph G is the minimum number of pebbles required such that the set of edges that contain pebbles form an edge dominating set S of G, for the initial configuration of pebbles can be altered by a sequence of pebbling moves and it is denoted by ψe(G) for a graph G. In this paper, we determine ψe(G) for Generalized Petersen graph, Jewel graph and Triangular snake graph.
- Research article
- https://doi.org/10.61091/um126-10
- Full Text
- Utilitas Mathematica
- Volume 126
- Pages: 195-222
- Published Online: 07/03/2026
Let W = {w1, w2, w3, …, wk} be an ordered set of vertices in a connected graph G. The representation of a vertex v ∈ V(G) with respect to W is the k-tuple r(v|W) = (d(v, w1), d(v, w2), …, d(v, wk)), where d(v, wi) is the length of the shortest path from v to wi. If each vertex in G is uniquely identified by the distance vector, r(v|W) = (d(v, w1), d(v, w2),…,d(v, wk)), then W is called a resolving set for G. If the resolving set is also independent, it is referred to as an independent resolving set. The independent metric dimension of G, denoted by idim(G), is the smallest cardinality of an independent resolving set. This study explores the independent metric dimension of the circulant graphs Cn(1, 2), Cn(1, 2, 3), Cn(1, 2, 3, 4) for sufficiently large n.
- Research article
- https://doi.org/10.61091/um126-09
- Full Text
- Utilitas Mathematica
- Volume 126
- Pages: 187-194
- Published Online: 07/03/2026
In this paper, given a homeomorphism f of a compact metric space X, we show that the set of all asymptotic average shadowable points of f is an open and invariant set and f has the asymptotic average shadowing property if and only if the set of all asymptotic average shadowable points of f is X if and only if any Borel probability measure μ of X has the asymptotic average shadowing property.
- Research article
- https://doi.org/10.61091/jcmcc130-10
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 130
- Pages: 137-149
- Published Online: 20/02/2026
In this paper we study group divisible designs (GDDs) with block size 4 and two groups of different sizes when λ2 = 1. We obtain necessary conditions for the existence of such GDDs and prove that these necessary conditions are sufficient in several cases. Further, we present general constructions using resolvable designs.
- Research article
- https://doi.org/10.61091/jcmcc130-09
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 130
- Pages: 123-136
- Published Online: 20/02/2026
In 1940, Birkhoff posed an open problem of counting all finite lattices on n elements. Recently, Bhavale counted all non-isomorphic lattices on n elements, containing up to four reducible elements, and having nullity up to three. Further, Aware and Bhavale counted all non-isomorphic lattices on n elements, containing up to five comparable reducible elements, and having nullity up to three. In this paper, we count all non-isomorphic lattices on n elements, containing five reducible elements, and having nullity three.
- Research article
- https://doi.org/10.61091/jcmcc130-08
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 130
- Pages: 107-121
- Published Online: 14/02/2026
The unit graph of a commutative ring with a non-zero identity is a graph with vertices as ring elements, and there is an edge between two distinct vertices if their sum is a unit. This study investigates the decomposition of the unit graph by examining its induced subgraphs and analyze key graph invariants, such as connectivity, diameter, and girth, for a finite local ring. We further decompose the unit graph of certain finite commutative rings into fundamental structures, such as cycle and star graphs.




