Notes on Fourier series (IV): Summability (R2)

Abstract

1.1. There are two familiar methods of summation of divergent series usually called the methods (R, 1) and (R, 2). If sn = u0 + u1 + … + un and, as it will be convenient to suppose throughout, u0 = 0, thenwhen h → + 0§: the convergence of the series for small positive h is presupposed.