English

Rainbow Numbers for the Generalized Schur Equation $x_1 + x_2 + \cdots + x_{m-1} = x_m$

Combinatorics 2024-01-17 v1 Number Theory

Abstract

We consider the rainbow Schur number RSm(n)RS_m(n), defined to be the minimum number of colors such that every coloring of {1,2,,n}\{1,2,\ldots,n\}, using all RSm(n)RS_m(n) colors, contains a rainbow solution to the equation x1+x2++xm1=xmx_1+x_2+\cdots +x_{m-1}=x_m. Recently, the exact values of RS3(n)RS_3(n) and RS4(n)RS_4(n) were determined for all nn. In this paper, we expand upon this work by providing a formula for RSm(n)RS_m(n) that holds for all m4m \geq 4 and all nn. A weakened version of the rainbow Schur number is also considered, for which one seeks solutions to the above-mentioned linear equation where, for a fixed tmt \leq m, at least tt colors are used.

Keywords

Cite

@article{arxiv.2401.07357,
  title  = {Rainbow Numbers for the Generalized Schur Equation $x_1 + x_2 + \cdots + x_{m-1} = x_m$},
  author = {Mark Budden and Bruce Landman},
  journal= {arXiv preprint arXiv:2401.07357},
  year   = {2024}
}