1. V.YEGNANARAYANAN - Department of Mathematics, Kalasalingam Academy for Research and Education, Deemed to
be University, Krishnankoil-626126, TN, India.
2. M. ANITHA - Department of Mathematics, Kalasalingam Academy for Research and Education, Deemed to
be University, Krishnankoil-626126, TN, India.
3. NOEMI C. ROHATINOVICI - Polytechnic University of Timişoara and Aurel Vlaicu University of Arad, Arad, Romania
Valentina.
4. E. BALAS - Department of Automation Industrial Engineering, Textiles and Transport, University, Aurel
Vlaicu, Arad, Romania.
The problem concerning vertex coloring of distance graphs are keenly pursued due to the motivation by the famous Hadwiger-Nelson plane coloring problem(HNP) concerning unit distance graphs. HNP asks for the minimum number of colors required for coloring the points of the two dimensional plane that are separated by a unit distance. In this paper we determine the chromatic number of distance graphs whose distance sets consists of different types of Pythagorean numbers and Semiprime numbers. Keywords: Distance Graphs, Chromatic number, Pythagorean distance graph, twice Pythagorean distance graph, thrice Pythagorean distance graph, Semiprime distance graph.
CHROMATIC COLORING OF DISTANCE GRAPHS II