
doi: 10.37236/1759
Let $G^{\times}_{+}$ be the graph on the vertex-set the positive integers ${\Bbb{N}}$, with $n$ joined to $m$ if $n\neq m$ and for some $x,y\in{\Bbb{N}}$ we have $x+y=n$ and $x\cdot y=m$. A pair of triangles sharing an edge (i.e., a $K_4$ with an edge deleted) and containing three consecutive numbers is called a $2$-fan, and three triangles on five numbers having one number in common and containing four consecutive numbers is called a $3$-fan. It will be shown that $G^{\times}_{+}$ contains $3$-fans, infinitely many $2$-fans and even arbitrarily large "bundles" of triangles sharing an edge. Finally, it will be shown that $\chi\big(G^{\times}_{+}\big)\ge 4$.
Coloring of graphs and hypergraphs, /dk/atira/pure/subjectarea/asjc/2600/2607, chromatic number, Diophantine equations, Other combinatorial number theory, Ramsey theory, name=Discrete Mathematics and Combinatorics, graph on integers
Coloring of graphs and hypergraphs, /dk/atira/pure/subjectarea/asjc/2600/2607, chromatic number, Diophantine equations, Other combinatorial number theory, Ramsey theory, name=Discrete Mathematics and Combinatorics, graph on integers
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 1 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
