2.8. The space rqð Þ <sup>u</sup>; <sup>p</sup>

Sheikh and Ganie [16] introduced the Riesz sequence space <sup>r</sup><sup>q</sup>ð Þ <sup>u</sup>; <sup>p</sup> and studied its various topological properties where u ¼ ð Þ uk is a sequence such that uk 6¼ 0 for all k ∈ N and qk � � the sequence of positive numbers and

$$Q\_n = \sum\_{k=0}^n q\_{k'} \forall n \in \mathbb{N}$$

Then, the matrix R<sup>q</sup> <sup>u</sup> ¼ r q nk � � of the Riesz mean Ru; qn � � is given by

$$r\_{nk}^q = \begin{cases} \frac{\mu\_k q\_k}{Q\_n} & \text{if } \ 0 \le k \le n, \\\ 0, & \text{if } \ k > n. \end{cases}$$

The Riesz mean Ru; qn � � is regular if and only if Qn ! <sup>∞</sup> as <sup>n</sup> ! <sup>∞</sup>.
