Ninth and tenth order virial coefficients for hard spheres in D dimensions

We evaluate the virial coefficients B-k for k <= 10 for hard spheres in dimensions D = 1 (....) 8. Virial coefficients with k even are found to be negative when D >= 5. This provides strong evidence that the leading singularity for the virial series lies away from the positive real axis when D >= 5. Further analysis provides evidence that negative virial coefficients will be seen for some k > 10 for D = 4, and there is a distinct possibility that negative virial coefficients will also evetually occur for D = 3.