TSTST 2023 Problem 3
Find all positive integers for which it is possible to color some cells of an infinite grid of unit squares red, such that each rectangle consisting of exactly cells (and whose edges lie along the lines of the grid) contains an odd number of red cells.
Dataset text NuminaMath olympiads. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.