期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2021; 16 (1)
In this work we study the zeros of the Eulerian and Bell polynomials and their generalizations. More concretely, lower estimates for the leftmost zero......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2021; 16 (1)
Let A = {a(0,) a(1), ..., a(k-1)} be a nonempty finite subset of an additive abelian group G. For a positive integer h (<= k), we let h((+/-) over ......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2021; 16 (1)
Let h be a function defined on E(G) with h(e) is an element of [0, 1] for any e is an element of E(G). Set d(G)(h)(x) = Sigma(e(sic)x) h(e). If g(x) &......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2020; 15 (2)
Researchers in the past have studied eigenvalues of Cayley digraphs or graphs. We are interested in characterizing Cayley digraphs on a finite commuta......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2020; 15 (2)
In this note, we show that 2-tuple dominating independent number of the Erdos-Renyi graph G(n,p) a.a.s. has a two-point concentration when p is a cons......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2020; 15 (2)
By means of quadratic transformations for the well-poised hypergeometric series, several reduction and transformation formulae are derived for the tri......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2019; 14 (1)
Recently, Sun defined a new sequence a(n) = Sigma(n)(k=0) ((n)(2k)) ((2k)(k)) 1/2k-1, which can be viewed as an analogue of the Motzkin numbers. Sun c......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2019; 14 (1)
We study Boltyanski's illumination problem (or Hadwiger's covering problem) for the class of convex bodies in R-n consisting of convex hulls of a pair......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2019; 14 (1)
A P->= n-factor means a path factor with each component having at least n vertices, where n >= 2 is an integer. A graph G is called a P->= n-......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2019; 14 (1)
The feedback vertex number tau(G) of a graph G is the minimum number of vertices that can be deleted from G such that the resultant graph does not con......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2019; 14 (1)
Recently, Ballantine and Merca proved that if (a, b) is an element of {(6, 8), (8,12), (12,24), (15,40), (16,48), (20,120), (21,168)}, then Sigma(ak+1......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2019; 14 (1)
We study the 2-adic behavior of the number of domino tilings of a 2(2n + 1) x 2(2n + 1) torus. We show that this number is of the form 2(4n+2) g(n)(2)......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2017; 11 (2)
Let G = (V, E) be a simple connected graph with vertex set V and edge set E. The Wiener-type invariants of G = (V, E) can be expressed in terms of the......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2017; 12 (1)
Let W(n) denote the number of partitions of n into powers of 2 such that for all i >= 0, 2(2i) and 2(2i+1) cannot both be parts of a particular par......
期刊: CONTRIBUTIONS TO DISCRETE MATHEMATICS, 2017; 12 (2)
Let G be a finite connected simple graph with a vertex set V (G) and an edge set E(G). A total signed dominating function of G is a function f : V (G)......