  We study the out-of-equilibrium current through an interacting quantum dot
modelled as an Anderson impurity contacted by two BCS superconductors held at
fixed voltage bias. In order to account for multiple Andreev reflections, we
develop a Keldysh Green's function scheme perturbative in the dot's interaction
strength. We find an unexpected enhancement of the current due to repulsive
interactions for small lead-to-dot couplings.
