Cyclic Latin Eulerian Numbers

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 $\Sigma (L_{\pi })=n\mathrm{asc}(\pi )+\pi (1)-\pi (n)$, yielding a closed-form expression for the cyclic Latin-Eulerian polynomial.

15 pages