Thailand IMO Training 2019, 2021, 2024. Covers soft techniques that people often subconsciously use to probe problems. Attached files are from 2021.
Thailand IMO Training 2020. Thue-Morse sequence, substitution systems, and Sturmian words.
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A chart showing the travel times from MacGregor to each MBTA metro station, including which station to board the T at.

Thailand IMO Training 2019. Literally just a list of college competition problems that are olympiad-y.
Thailand IMO Training 2019. A fun problem set based on the idea that you can construct programs of all sorts in the medium of polynomials.
Thirty-three thousand feet in the air,
I am full of hope and despair.Thailand IMO Training 2018. Problems on approximations of real numbers by rationals, the Farey sequence, and irrationality measure. Ends with an outline of Apery's proof that ζ(3) is irrational.
A daily journal of my experience at MOP 2017, both the math part and the non-math part.
Thailand IMO Training 2018. Δf(x) := f(x+1)-f(x). A collection of problems on my favorite Olympiad technique: finite differences
Thailand IMO Training 2018. Construction problems, with a focus on just do it, or greedy, construction.
you have filtered everything out…