English

Regular $K_3$-irregular graphs

Combinatorics 2025-07-28 v1 Discrete Mathematics

Abstract

We address the problem proposed by Chartrand, Erd\H{o}s and Oellermann (1988) about the existence of regular K3K_3-irregular graphs. We first establish bounds on the K3K_3-degrees of such graphs and use them to prove that there are no such graphs with regularities at most 77. For the regularity 88, we narrow down the bounds on the order of such graphs to six possible values. We then present an explicit example of a 99-regular K3K_3-irregular graph. Finally, we discuss an evolutionary algorithm developed to discover more examples of rr-regular K3K_3-irregular graphs for consecutive values r{9,,30}r \in \{9, \dots, 30\}.

Keywords

Cite

@article{arxiv.2507.18776,
  title  = {Regular $K_3$-irregular graphs},
  author = {Artem Hak and Sergiy Kozerenko and Andrii Serdiuk},
  journal= {arXiv preprint arXiv:2507.18776},
  year   = {2025}
}

Comments

Preliminary version, any comments are welcome