Cyclic Latin Eulerian Numbers

Source abstract

We introduce the directed cyclic difference inventory $D_n(\mathbf{m})$ to study Latin Eulerian numbers restricted to row-reorderings of the cyclic Latin square, offering an orientation-sensitive refinement of the prescribed-edge-length Hamiltonian path problem. We establish exact enumeration formulas, symmetries, and realizability obstructions for this inventory. Furthermore, we reduce the cyclic total-ascent statistic directly to endpoint-refined Eulerian statistics via the identity $Σ(L_π) = n \operatorname{asc}(π) + π(1) - π(n)$, yielding a closed-form expression for the cyclic Latin-Eulerian polynomial.