2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/223131We study the convergence of certain subseries of the harmonic series corresponding to increasing sequences of integers whose digits in a certain base are not uniformly distributed. We also discuss the case of irregular sequences, where the frequency distribution of some of the digits does not exist. Examples are given for irregular sequences where the corresponding harmonic subseries is convergent, or divergent, respectively.No part was published or presented beforeNumber Theory11K36text