Combinatorics
Tuesday, January 24
![Jan24](Jan24.png)
Blackboards
- Integers not divisible by 2, 3, 5
- Möbius inversion
- Fixed-point free permutations (derangements)
Thursday, January 26
![Jan26](Jan26.png)
Blackboards
- The sum 1 + 2 + … + n and difference calculus
- Bars & stars for counting monomials