Abstract
We introduce an order on the set of nondivisorial ideals of a numerical semigroup $S$, and link antichains of this order with the star operations on $S$; subsequently, we use this order to find estimates on the number of star operations on $S$. We then use them to find an asymptotic estimate on the number of nonsymmetric numerical semigroups with $n$ or less star operations, and to determine these semigroups explicitly when $n=10$.
Citation
Dario Spirito. "Star operations on numerical semigroups: antichains and explicit results." J. Commut. Algebra 11 (3) 401 - 431, 2019. https://doi.org/10.1216/JCA-2019-11-3-401
Information