Combinatorics

Week 1 | Week 2 | Week 3

Tuesday, January 24

Blackboards

• Integers not divisible by 2, 3, 5
• Möbius inversion
• Fixed-point free permutations (derangements)

Thursday, January 26

Blackboards

• The sum 1 + 2 + … + n and difference calculus
• Bars & stars for counting monomials