Counting with Categories

You can see some lecture notes for a minicourse on combinatorics that I’m teaching at the Summer School on Algebra at the Zografou campus of the National Technical University of Athens. Since the formatting works more nicely on the n-Category Café I’ll just point you there:

• Counting with categories (part 1)—species and their generating functions; the category of species.
• Counting with categories (part 2)—the 2-rig of species; counting binary trees.
• Counting with categories (part 3)—substi...