  Motivated by the AdS_6/CFT_5 correspondence, we study general supersymmetric
solutions of massive type IIA supergravity, consisting of a warped product of
six-dimensional anti-de Sitter space AdS_6 with a four-dimensional Riemannian
manifold M_4, and fluxes compatible with the SO(5,2) symmetry. We find that the
only local solution of this form is the warped AdS_6 x_w S^4 solution,
originally discovered by Brandhuber and Oz. We discuss the supersymmetric
properties of this solution.
