Numerical semigroups of Szemerédi type

Given any length k ≥ 3 and density 0 < δ ≤ 1, we introduce and study the set Sz(k, δ) consisting of all positive integers n such that every subset of {1, 2, . . . , n} of density at least δ contains an arithmetic progression of length k. A famous theorem of Szemerédi guarantees that this set is n...

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Detalles Bibliográficos
Autores: Adhikari, S. D., Boza Prieto, Luis, Eliahou, Shalom, Revuelta Marchena, María Pastora, Sanz Domínguez, María Isabel
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2019
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/135998
Acceso en línea:https://hdl.handle.net/11441/135998
https://doi.org/10.1016/j.dam.2018.03.023
Access Level:acceso abierto
Palabra clave:Arithmetic progression
van der Waerden number
Multiplicity
Frobenius numbe
Conductor
Descripción
Sumario:Given any length k ≥ 3 and density 0 < δ ≤ 1, we introduce and study the set Sz(k, δ) consisting of all positive integers n such that every subset of {1, 2, . . . , n} of density at least δ contains an arithmetic progression of length k. A famous theorem of Szemerédi guarantees that this set is not empty. We show that Sz(k, δ)∪{0} is a numerical semigroup and we determine it for (k, δ) = (4, 1/2) and for more than thirty pairs (3, δ) with δ > 1/5.