Savas, EkremRhoades, B. E.2025-05-102025-05-1020071521-13982-s2.0-40849120253https://hdl.handle.net/20.500.14720/17554We obtain necessary and sufficient conditions for the series Sigma a(n) summable \A\ to imply that Sigma a(n)lambda(n) is summable \B\(k), and for the series Sigma(an) summable \A\(k) to imply that Sigma a(n)lambda(n) is summable \B\, k >= 1 where A and B are lower triangular matrices.eninfo:eu-repo/semantics/closedAccessAbsolute SummabilitySummability FactorArticle93N/AQ4319336WOS:000244874900006