9 citations · 15 across the 3 of their papers we have counts for
3 papers
math.CO2008★ 5 cited
The classical umbral calculus: Sheffer sequences
E. Di Nardo, H. Niederhausen, D. Senato
Following the approach of Rota and Taylor \cite{SIAM}, we present an innovative theory of Sheffer sequences in which the main properties are encoded by using umbrae. This syntax al…
math.CO2007★ 1 cited
Pattern Avoiding Ballot Paths and Finite Operator Calculus
Heinrich Niederhausen, Shaun Sullivan
Counting pattern avoiding ballot paths begins with a careful analysis of the pattern. Not the length, but the characteristics of the pattern are responsible for the difficulties in…
math.CO2007★ 9 cited
Euler Coefficients and Restricted Dyck Paths
Heinrich Niederhausen, Shaun Sullivan
We consider the problem of enumerating Dyck paths staying weakly above the x-axis with a limit to the number of consecutive up steps, or a limit to the number of consecutive down s…