Matrix summability method

Summary

A matrix summability method uses an infinite matrix $A = (a_{nk})$ to turn a sequence $(s_k)$ into the weighted sums $\sum_k a_{nk} s_k$. The method then takes the limit of these sums. Most classical summability methods, such as Cesàro summation, Nörlund means and Euler summation, are of this kind. Their properties can be read off from the entries of the matrix, as in the Silverman–Toeplitz theorem and the Kojima–Schur theorem.