5 citations · 5 across the 12 of their papers we have counts for
15 papers
Hamiltonian paths in iterated line graphs
Jan Ekstein, Zuzana Kulhánková
For integer , the -iterated line graph of an undirected graph is defined to be , where is the line graph of . In this paper we…
The most general structure of graphs with hamiltonian or hamiltonian connected square
J. Ekstein, H. Fleischner
On the basis of recent results on hamiltonicity and hamiltonian connectedness in the square of a 2-block, we determine the most general block-cutvertex structure a graph may ha…
Hamiltonian properties in generalized lexicographic products
Jan Ekstein, Jakub Teska
The lexicographic product of two graphs and is obtained from by replacing each vertex with a copy of and adding all edges between any pair of copies correspo…
A Best Possible Result for the Square of a 2-Block to be Hamiltonian
Jan Ekstein, Herbert Fleischner
It is shown that for any choice of four different vertices x_1,...,x_4 in a 2-block G of order p>3, there is a hamiltonian cycle in G^2 containing four different edges x_iy_i of E(…
3-coloring triangle-free planar graphs with a precolored 9-cycle
Ilkyoo Choi, Jan Ekstein, Přemysl Holub +1
Given a triangle-free planar graph G and a 9-cycle C in G, we characterize situations where a 3-coloring of C does not extend to a proper 3-coloring of G. This extends previous res…
Revisiting the Hamiltonian Theme in the Square of a Block: The Case of DT-Graphs
Gek L. Chia, Jan Ekstein, Herbert Fleischner
The square of a graph G, denoted G^2, is the graph obtained from G by joining by an edge any two nonadjacent vertices which have a common neighbor. A graph G is said to have the F_…