Feb 7: Catalan numbers (cont). Stirling numbers and
cycles in permutations.
Feb 9: Cycles in permutations (cont). No small cycles
and all even cycles. Set partitions again.
Feb 14: Exponential formula for labelled objects.
Examples: 2-regular graphs, graphs by components, rooted
labelled trees.
Feb 14 (this class substitute the class of Thursday
February 16):
Exponential formula for unlabelled objects. Integer
partitions. Rooted unlabelled trees.
Feb 16: Midterm test #1.
Reading week: no lectures this week.
Feb 28: Comments about midterm and assignment 1.
Finite fields. Restricted components.
Mar 1: Dirichlet generating functions and Mobius
inversion. Bivariate generating functions and moments.