Sequence Characterization of Multiple Almost-Riordan Arrays and Their Compressions

Abstract: This is the second paper of the paper series on multiple Riordan arrays. In this paper, based on the study of multiple Riordan arrays and the multiple Riordan group, we define multiple almost-Riordan arrays and find that the set of all multiple almost-Riordan arrays forms a group, called the multiple almost-Riordan group. We also obtain the sequence characteristics of multiple almost-Riordan arrays and give the production matrices for multiple almost-Riordan arrays. We define the compression of multiple almost-Riordan arrays and provide their sequence characterization.