Not exactly the most frequent mathematical object in the literature, however, here is an interesting instance where this quantity occurs.

Take the the statistical average of $\prod_{i,j} a_{ij}$ over a unitary $n\times n$ matrix $A$ chosen uniformly at random (i.e., Haar-distributed). Showing this expectation is nonzero for $n$ even is <a href="https://www.sciencedirect.com/science/article/pii/S0012365X15000473">equivalent to the Alon-Tarsi conjecture</a>.