English

A note on potentially $K_4-e$ graphical sequences

Combinatorics 2007-05-23 v1

Abstract

A sequence SS is potentially K4eK_4-e graphical if it has a realization containing a K4eK_4-e as a subgraph. Let σ(K4e,n)\sigma(K_4-e, n) denote the smallest degree sum such that every nn-term graphical sequence SS with σ(S)σ(K4e,n)\sigma(S)\geq \sigma(K_4-e, n) is potentially K4eK_4-e graphical. Gould, Jacobson, Lehel raised the problem of determining the value of σ(K4e,n)\sigma (K_4-e, n). In this paper, we prove that σ(K4e,n)=2[(3n1)/2]\sigma (K_4-e, n)=2[(3n-1)/2] for n7n\geq 7, and n=4,5,n=4,5, and σ(K4e,6)=20\sigma(K_4-e, 6)= 20.

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Cite

@article{arxiv.math/0308105,
  title  = {A note on potentially $K_4-e$ graphical sequences},
  author = {Chunhui Lai},
  journal= {arXiv preprint arXiv:math/0308105},
  year   = {2007}
}

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5 pages