Math 172: Combinatorics



Instructor: Sergei Korotkikh
E-mail: "last name" AT berkeley DOT edu
Office: 843 Evans Hall


Syllabus: here


Class Meetings: Mondays, Wednesdays, and Fridays. 11:00AM-11:59AM. 3109 Etcheverry.


Office Hours: 3PM-4PM Mon, 6PM-7PM Wed (via Zoom), 12:30PM-1:30PM Fri.


E-mail: All e-mail correspondence should have the subject line starting from "Math 172:".


Recommended textbook (optional, some part of the lecture material will differ from the book):
A Walk Through Combinatorics (4th Edition) by Miklós Bóna.


Grade: Homeworks (30% of the grade), Midterm (25% of the grade), Final (45% of the grade).


Homeworks: Generally, problem sets will be posted on Friday after class and will be due on Gradescope by the end of the next Friday. There will be a couple of exceptions to this schedule, due to holidays and on the week of the midterm. Feel free to work together on homework problems, but your solutions must be written up independently and reflect your own understanding of the material. The lowest homework score will be dropped in the end of the semester. No late homeworks will be accepted, unless there are specific accommodations arranged beforehand with the instructor.


Bonus problems: Majority of the homeworks will include an optional problem of increased difficulty. These problems are intended to be hard and are purely optional, but solving them will give an extra credit in the end of the semester, which will be capped at 5% of the final grade.



Schedule:

DateTopic HomeworkNotes
August 23Intro, pigeon-hole principle   
August 25Weak induction Problem Set 1 posted, due 09/01 
August 28Strong induction, counting problems  
August 30Counting problems (cont.)   
September 1Binomial coefficients Problem set 2 posted, due 09/08  
September 4No class   Labor day
September 6Binomial theorem    
September 8Multinomial theorem, compositions Problem set 3 posted, due 09/15  
September 11Compositions (cont.), set partitions   
September 13Partitions  
September 15Partitions, permutationsProblem Set 4 posted, due 09/22 
September 18Cycle types of permutations  
September 20Stirling numbers  
September 22Inclusion-Exclusion PrincipleProblem Set 5 posted, due 09/29 
September 25Formal power series  
September 27Formal power series (cont.)  
September 29Linear recurrence relations  
October 2Generalized binomial theorem  
October 4Binomial theorem (cont.)  
October 6MidtermProblem set 6 posted, due 10/13 
October 9Catalan numbers  
October 11Catalan numbers (cont.)  
October 13PartitionsProblem set 7 posted, due 10/20 
October 16Pentagonal number theorem  
October 18Exponential generating functions  
October 20Graphs, Eulerian trailsProblem set 8 posted, due 10/27 
October 23Eulerian trails (cont.)  
October 25Hamiltonian cycles  
October 27Isomorphisms of graphsProblem set 9 posted, due 11/03 
October 30Trees  
November 1Cayley's theorem  
November 3Kruskal's algorithmProblem set 10 posted, due 11/10 
November 5Bipartite graphs  
November 7Hall's theorem  
November 10No classProblem set 11 posted, due 11/17 Veterans day
November 13Turan's Theorem  
November 15Tutte's theorem, chromatic polynomial