# Eric Rowland (Hofstra University)

##### Date

Friday September 24, 20212:30 pm - 3:30 pm

##### Location

Online via Zoom## Math & Stats Department Colloquium

**Friday, September 24th, 2021**

**Time:** 2:30 p.m. **Place:** Online (via Zoom)

**Speaker:** Eric Rowland (Hofstra University)

**Title:** Congruences for some sequences arising in combinatorics.

**Abstract:** Over the last 15 years there have been a number of papers studying congruence properties of sequences such as the Catalan numbers that arise in combinatorial settings. Proofs of these properties have relied on methods particular to each sequence. However, by realizing a sequence as the diagonal of a rational power series in multiple variables, we can compute congruence information modulo prime powers in a completely automatic way. This approach reduces the proofs of many known results to routine computations, establishes new theorems for well-known sequences, and allows us to resolve some conjectures about the Apery numbers.

**Eric Rowland** is an Associate Professor of Mathematics at Hofstra University. Before joining Hofstra, he held postdoctoral positions at Tulane University, the University of Waterloo, the University of Quebec at Montreal, and the University of Liege. He got his Ph.D. in Mathematics in 2009 from Rutgers University. He studies arithmetic properties of integer sequences that arise in combinatorial settings. His research involves a nice mix of number theory, combinatorics, and theoretical computer science.