Approximation by Nörlund means with respect to Vilenkin system in Lebesgue spacesIn this paper we improve and complement a result by Móricz and Siddiqi \cite{Mor}. In particular, we prove that their estimate of the Nörlund means with respect to the Vilenkin system holds also without their additional condition. Moreover, we prove a similar approximation result in Lebesgue spaces for any $1\leq p<\infty$.
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