#### G. Canan Hazar Güleç, Merve İlkhan, A new characterization of absolute summability factors, Vol. 2020 (2020), Article ID 15, pp. 1-11

Full Text: PDF
DOI: 10.23952/cot.2020.15

Received April 20, 2020; Accepted May 30, 2020; Published June 22, 2020

Abstract. By $(A,B)$, we denote the set of all sequences $\lambda=(\lambda_n)$ such that $\sum x_n\lambda_n$ is summable $B$ whenever $\sum x_n$ is summable $A,$ where $A$ and $B$ are two methods of summability. In this paper, we characterize the sets $(\vert \overline{N},p_{n},u_{n}\vert_{k},$ $\vert \Phi \vert)$, $(\vert \Phi, u_{n}\vert_{k},$ $\vert \overline{N},p_n\vert)$ and $(\vert \overline{N},p_n\vert, \vert \Phi, u_n\vert_k$, $(\vert \Phi \vert,$ $\vert \overline{N},$  $p_n, u_n\vert_k)$ for $1\leq k<\infty$.