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Work in Progress

2025 · Aug-Nov Term

Find all notes from class here. Note: unedited and real-time, so expect these to be generally sloppy, illegible, and mostly useless, but hopefully also mostly harmless :)

DateLecture
06 Oct, 2025MidSem Review
Explored some properties of kings in tournaments.
See this article on the The King Chicken Theorems by Stephen B. Maurer for more.
07 Oct, 2025Birkhoff–von-Neumann Theorem
See the wikiedia entry on the topic for a proof. Slides from class.
10 Oct, 2025Picture-Hanging Puzzles
See this paper for more context.
13 Oct, 2025100 Prisoners Puzzle
See this nice video by Veritasium and the wikipedia page.
14 Oct, 2025Linear Algebra with Oddtown
See the first part of this document for the approach discussed in class, Theorem 1.1 here for a determinant-based argument for linear independence, and Theorem 2 here for a combinatorial argument
17 Oct, 2025Nimbers – I
See this essay for a build up of the XOR strategy.
20 Oct, 2025Nimbers – II
For further reading, check out transfinite Nim.
24 Oct, 2025Counting Incomplete Cubes
Phenomenal tour of the problem by Paul Duncstep here.
27 Oct, 2025Group Actions with Tic-Tac-Toe
Check out the Numberphile take on this problem.
28 Oct, 2025Burnside with Colored Squares
We analyzed the number of squares whose edges have been colored with three colors (where not every color has to necessarily appear) discounting symmetries. Find more practice problems in this worksheet.
31 Oct, 2025Permutation Puzzles
This material was inspired by this course. In particular, download the course book and look at section 5.2 for the questions discussed in class.
General challenge: can you figure out how Penn and Teller were fooled here?
03 Nov, 2025Rubik Cube + Commutators
This class was a poor imitation of Ramprasad’s amazing talk on the topic. You can find the cubing demos here. The material on solving equations was out of scope for our class, but you are welcome to explore it as further reading!
04 Nov, 2025Commutators Continued
In this class we went over the commutator theorem.
10 Nov, 2025Card Magic · Ternary and Binary
For practice with ternary representations, see the 27 card trick · For an application of binary representations, check out any card to any position using only perfect in and out shuffles.
11 Nov, 2025Basic Number Theory
We mostly focused on the Fundamental Theorem of Arithmetic.
See the following essays by Gowers on the topic for additional reading: Why isn’t the fundamental theorem of arithmetic obvious? and Proving the fundamental theorem of arithmetic
14 Nov, 2025Enigma
See Rejewski’s 1980 paper and these notes.
17 Nov, 2025Same-Size Intersections
We did another example of applying the linear algebraic method.
See the book Thirty-three Miniatures: Mathematical and Algorithmic Applications of Linear Algebra by Matoušek for more examples. What we discussed in class was based on Miniature #4.