Conjecture of Wilf: a survey

M Delgado - Numerical Semigroups: IMNS 2018, 2020 - Springer
This paper intends to survey the vast literature devoted to a problem posed by Wilf in 1978
which, despite the attention it attracted, remains unsolved. As it frequently happens with …

[HTML][HTML] Gapsets and numerical semigroups

S Eliahou, J Fromentin - Journal of Combinatorial Theory, Series A, 2020 - Elsevier
For g≥ 0, let ng denote the number of numerical semigroups of genus g. A conjecture by
Maria Bras-Amorós in 2008 states that the inequality ng≥ ng− 1+ ng− 2 holds for all g≥ 2 …

Numerical semigroups, polyhedra, and posets I: the group cone

N Kaplan, C O'Neill - arXiv preprint arXiv:1912.03741, 2019 - arxiv.org
Several recent papers have explored families of rational polyhedra whose integer points are
in bijection with certain families of numerical semigroups. One such family, first introduced …

When is a numerical semigroup a quotient?

T Bogart, C O'NEILL, K Woods - Bulletin of the Australian …, 2024 - cambridge.org
A natural operation on numerical semigroups is taking a quotient by a positive integer. If, the
first known family of numerical semigroups that cannot be written as a k-quotient. We also …

Increasingly Enumerable Submonoids of : Music Theory as a Unifying Theme

M Bras-Amorós - The American Mathematical Monthly, 2020 - Taylor & Francis
We analyze the set of increasingly enumerable additive submonoids of R, for instance, the
set of logarithms of the positive integers with respect to a given base. We call them ω …

[HTML][HTML] Counting numerical semigroups by genus and even gaps

M Bernardini, F Torres - Discrete Mathematics, 2017 - Elsevier
Let ng be the number of numerical semigroups of genus g. We present an approach to
compute ng by using even gaps, and the question: Is it true that n g+ 1> ng? is investigated …

Numerical semigroups and Kunz polytopes

E Alhajjar, T Russell, M Steward - Semigroup Forum, 2019 - Springer
A numerical semigroup S is an additive submonoid of NN whose complement is finite. The
cardinality of N _0 \ SN 0\S is called the genus of S and is denoted by g (S). The first nonzero …

The right-generators descendant of a numerical semigroup

M Bras-Amorós, J Fernández-González - Mathematics of Computation, 2020 - ams.org
For a numerical semigroup, we encode the set of primitive elements that are larger than its
Frobenius number and show how to produce in a fast way the corresponding sets for its …

Numerical semigroups from rational matrices II: matricial dimension does not exceed multiplicity

A Chhabra, SR Garcia, C O'NEILL - Bulletin of the Australian …, 2024 - cambridge.org
We continue our study of exponent semigroups of rational matrices. Our main result is that
the matricial dimension of a numerical semigroup is at most its multiplicity (the least …

On atoms of the set of generalized numerical semigroups with fixed corner element

M Bernardini, AS Castellanos, W Tenório, G Tizziotti - Semigroup Forum, 2024 - Springer
We study the atomic generalized numerical semigroups (GNSs), which naturally extend the
concept of atomic numerical semigroups. We introduce the notion of corner special gap and …