English

Reflective numerical semigroups

Number Theory 2022-07-04 v1

Abstract

We define a reflective numerical semigroup of genus gg as a numerical semigroup that has a certain reflective symmetry when viewed within Z\mathbb{Z} as an array with gg columns. Equivalently, a reflective numerical semigroup has one gap in each residue class modulo gg. In this paper, we give an explicit description for all reflective numerical semigroups. With this, we can describe the reflective members of well-known families of numerical semigroups as well as obtain formulas for the number of reflective numerical semigroups of a given genus or given Frobenius number.

Keywords

Cite

@article{arxiv.2207.00051,
  title  = {Reflective numerical semigroups},
  author = {Caleb M. Shor},
  journal= {arXiv preprint arXiv:2207.00051},
  year   = {2022}
}
R2 v1 2026-06-24T12:10:20.833Z