We compute the O(1) contribution to holographic c − a for IIB supergravity on AdS 5 × S 5 /Z n and on AdS 5 × T 1,1 /Z n . In both cases, we find agreement with the dual field theory results, thus providing 1/N 2 checks of AdS/CFT with reduced supersymmetry. Since the holographic computation involves a sum over shortened multiplets in the KK tower, we provide some details on the S 5 and T 1,1 spectra in a form that is convenient when considering their Z n orbifolds. The computation for the even Z n orbifolds of S 5 includes a sum over the multiplets in the twisted sector that is essential for obtaining agreement with the dual field theory.