Can you place numbers from 1 to 16 on a 4x4 grid, such that the distance between any two consecutive numbers ($a$ and $a+1$) is Manhattan distance 3?
Bonus question: can you also make 1 and 16 be separated by Manhattan distance 3, thus making it a closed tour?
Note that the Manhattan distance between two locations is the distance between their row locations plus the distance between their column locations.
Good luck!
