2 problems

Let $\beta\geq 2$ be a base. A pair $(a,b)$ is a reversed sum-product pair in base $\beta$ when the sum of $a$ and $b$, written in base $\beta$, is the reversal of the base-$\beta$…

Haddley and Worsley's conjecture. Every monohedral tiling is a subtiling of a radially generated tiling.