The generalized Ces\`{a}ro matrices of order three are supraposinormal on $\ell^2$

Abstract

The procedure that was used in an earlier paper on the generalized Ces\`{a}ro matrices of order two is adapted here to show that generalized Ces\`{a}ro matrices of order three are supraposinormal on $\ell^2$. This leads to information about their posinormality, coposinormality, and hyponormality. The reader is then invited to formulate a conjecture regarding generalized Ces\`{a}ro matrices of other orders.