All Questions

I have a $1\times n$ chessboard and $2$ pairs of kings in it. Both components of each pair of kings must be adjacent in the chessboard, that is, they must be attacking. Now, I want to calculate the ...

Given two coprime integers $a < b$ of different parities, only a finite number of points in $\mathbb N^2$ cannot be reached by a walk in $\mathbb N^2$, starting at the origin and using only steps ...

Starting somewhere on an infinite square grid, is it possible to visit every square exactly once, if at move $n$, one must jump $a_n$ steps in one of the directions north,south,east or west, and mark ...