
Mprime Seminar Series on Mathematics of Computer Algebra and AnalysisA method for determining the mod2^{k} behaviour of (certain) recursive sequences.Professor Christian KrattenthalerFakultät für Mathematik, Universität Wien.
Abstract: I shall present a (computersupported) method to obtain congruences modulo powers of 2 for sequences given by recurrences of finite depth with polynomial coefficients. I shall illustrate the method by applying it to Catalan numbers, and to subgroup counting functions associated with Hecke groups and related groups. Thereby numerous new results are obtained, including many extensions of known results to higher powers of 2. This is joint work with Thomas Müller. 