Square Integer Heffter Arrays with Empty Cells

D. S. Archdeacon, J. H. Dinitz, D. M. Donovan +1

A Heffter array $H(m,n;s,t)$ is an $m\times n$ matrix with nonzero entries from ${\mathbb{Z}}_{2ms+1}$ such that $i)$ each row contains $s$ filled cells and each column contains $t$…