On absolute generalized Norlund summability of double orthogonal series


Department of Mathematics and Computer Sciences, University of Prishtina Avenue "Mother Theresa " 5, Prishtin"e, 10000, KOSOV"{E}


In the paper [Y. Okuyama, {it On the absolute generalized N"{o}rlund summability of orthogonal series},
Tamkang J. Math. Vol. 33, No. 2, (2002), 161-165] the author has found some sufficient conditions under which an orthogonal series
is summable $|N,p,q|$ almost everywhere. These conditions are expressed in terms of coefficients of the series. It is the purpose of
this paper to extend this result to double absolute summability $|N^{(2)},mathfrak{p},mathfrak{q}|_k$, $(1leq kleq 2)$