On row-factorization relations of certain numerical semigroups

Abstract

Let [Formula: see text] be a numerical semigroup minimally generated by an almost arithmetic sequence. We give a description of a possible row-factorization (RF) matrix for each pseudo-Frobenius element of [Formula: see text] Further, when [Formula: see text] is symmetric and has embedding dimension four or five, we prove that the defining ideal is minimally generated by RF-relations.