2 problems

Let an $n \times n$ knight's tour be a closed knight's tour on an $n \times n$ board, and let a rail be the structure defined by the preceding discussion: a pair of edges that can…

Let $a$ and $b$ be positive integers satisfying … with $a$ and $b$ not both odd. An $(a,b)$ knight's tour is a cycle visiting every vertex of the corresponding knight's graph on…