{ "id": "2008.08110", "version": "v1", "published": "2020-08-18T18:14:36.000Z", "updated": "2020-08-18T18:14:36.000Z", "title": "Numerical Semigroups of small and large type", "authors": [ "Deepesh Singhal" ], "comment": "20 pages", "categories": [ "math.CO", "math.AC" ], "abstract": "A numerical semigroup is a sub-semigroup of the natural numbers that has a finite complement. Some of the key properties of a numerical semigroup are its Frobenius number F, genus g and type t. It is known that for any numerical semigroup $\\frac{g}{F+1-g}\\leq t\\leq 2g-F$. Numerical semigroups with $t=2g-F$ are called almost symmetric, we introduce a new property that characterises them. We give an explicit characterisation of numerical semigroups with $t=\\frac{g}{F+1-g}$. We show that for a fixed $\\alpha$ the number of numerical semigroups with Frobenius number $F$ and type $F-\\alpha$ is eventually constant for large $F$. Also the number of numerical semigroups with genus $g$ and type $g-\\alpha$ is also eventually constant for large $g$.", "revisions": [ { "version": "v1", "updated": "2020-08-18T18:14:36.000Z" } ], "analyses": { "keywords": [ "numerical semigroup", "large type", "frobenius number", "eventually constant", "finite complement" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }