2 papers
math.CO2026
Square roots in the Appell group and Sprugnoli arrays
Paul Barry
We introduce a special mapping from pairs of power series to the group of Sprugnoli matrices. This mapping has the property when the second argument is an even power series, then t…
math.CO2026
A new group in the Riordan family of matrix groups: the Sprugnoli group
Paul Barry
We define a group of lower-triangular matrices whose columns are defined by power series. This group can be seen as a generalization of the (ordinary) Riordan group and the double…