RT journal article T1 Digital numerical semigroups A1 Moreno Frías, María Ángeles A1 Rosales, José Carlos K1 Digital numerical semigroup K1 Frobenius number K1 genus K1 multiplicity K1 algorithm K1 covariety K1 Frobenius variety K1 Frobenius pseudo-variety AB The number of digits in base ten system of a positive integer n, is denoted by l(n). A digitalsemigroup is a subsemigroup D of (N\{0}, ·) such that if d ∈ D, then {x ∈ N\{0} | l(x) = l(d)} ⊆ D.Let A ⊆ N\{0}. Denote by L(A) = {l(a) | a ∈ A}. We will say that a numerical semigroup S is a digitalnumerical semigroup if there is a digital semigroup D such that S = L(D) ∪ {0}. In this work we show thatD = {S | S is a digital numerical semigroup} is a Frobenius variety, D(Frob=F) = {S ∈ D | F(S) = F} is acovariety and D(mult = m) = {S ∈ D | m(S) = m} is a Frobenius pseudo-variety. As a consequence wepresent some algorithms to compute D(Frob=F), D(mult = m) and D(gen = 1) = {S ∈ D | g(S) = 1}.If X ⊆ N\{0}, we denote by D[X] the smallest element of D containing X. If S = D[X], then we willsay that X is a D-system of generators of S. We will prove that if S ∈ D, then S admits a unique minimalD-system of generators, denoted by Dmsg(S). The cardinality of Dmsg(S) is called the D-rank of S. Wesolve the Frobenius problem to elements of D with D-rank equal to 1. Moreover, we present an algorithmicprocedure to calculate all the elements of D with fixed D-rank. PB Faculty of Sciences and Mathematics, University of Niˇs, Serbia YR 2024 FD 2024 LK http://hdl.handle.net/10498/35431 UL http://hdl.handle.net/10498/35431 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 10-may-2026