William J. Wesley, An elementary solution to the 2-color Pythagorean triples problem
In the 1980s, Ron Graham asked whether every red/blue coloring of the positive integers contains a monochromatic Pythagorean triple and offered a $100 prize for the answer. The bounty was claimed in 2016 by Heule, Kullmann, and Marek, who showed that every such coloring of has a monochromatic triple. Their proof used SAT solvers and …