AG Diskrete Mathematik |
14.10.2025 15:00 - 16:30
Abstract:
I will discuss two - unrelated - topics: (1) enumeration of two-rowed set-valued standard tableaux; (2) cyclic sieving for rooted plane trees. Obviously, I will explain what these topics are about. Maybe more important than the results are the lessons one can learn from the treatement of these problems: (1) enumeration problems for Motzkin paths are solved by the use of generating functions; (2) extraction of coefficients from power series involving implicitly defined functions is solved by the - appropriate! - application of Lagrange inversion; (3) how to prove integrality of factorial expressions and polynomiality of q-factorial expressions; (4) how to prove non-negativity of coefficients in such expressions. The second topic is joint with Mireille Bousquet-M\'elou.
