Abstract
The polynomial sequences of Sheffer type
are defined by the following generating function:
In this work, we are interested, with these sequences when they are also d-orthogonal polynomial sets, that is to say polynomials satisfying one standard
-order recurrence relation. We revisit some families in the literature and we state an explicit formula giving the exact number of Sheffer type d-orthogonal sets. We investigate, in details, the d-symmetric case and the particular case d=3.