A combinatorial interpretation of Guo and Zeng's q-Faulhaber   coefficients
  Recently, Guo and Zeng discovered q-analogues of Faulhaber's formulas for the sums of powers. They left it as an open problem to extend the combinatorial interpretation of Faulhaber's formulas as given by Gessel and Viennot to the q case. In this note we will provide such an interpretation. 
Martin Rubey