posted on 2025-05-10, 23:51authored byS. Ole Warnaar, W. Zudilin
The q-binomial coefficients [<sup>n</sup><sub>m</sub>] = ᴨ<sup>m</sup><sub>i=1</sub>(1-q<sup>n-m+i</sup>)/(1-q<sup>i</sup>), for integers 0≤m≤n, are known to be polynomials with non-negative integer coefficients. This readily follows from the q-binomial theorem, or the many combinatorial interpretations of [<sup>n</sup><sub>m</sub>]. In this note we conjecture an arithmetically motivated generalisation of the non-negativity property for products of ratios of q-factorials that happen to be polynomials.