2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101310In this article we introduce an isomorphism invariant for type II_1 factors using the Connes-Folner condition. We compute bounds of this number for free group factors.15 pages, submitted to the Journal of Functional AnalysisOperator AlgebrasGroup Theory46L35text