For every r, there exists S(r) such that any r-colouring of {1, …, S(r)} contains monochromatic x, y, x + y. Exact values: S(1)=2, S(2)=5, S(3)=14, S(4)=45, S(5)=161 (the last via SAT solving 2017). Rado's theorem generalises to…
For every r, there exists S(r) such that any r-colouring of {1, …, S(r)} contains monochromatic x, y, x + y. Exact values: S(1)=2, S(2)=5, S(3)=14, S(4)=45, S(5)=161 (the last via SAT solving 2017). Rado's theorem generalises to…