  Fourier series solutions to the deflection and magnification by a family of
three-dimensional cusped two power-law ellipsoidal mass distributions are
presented. The cusped two power-law ellipsoidal mass distributions are
characterized by inner and outer power-law radial indices and a break (or,
transition) radius. The model family includes mass models mimicking Jaffe,
Hernquist, and $\eta$ models and dark matter halo profiles from numerical
simulations. The Fourier series solutions for the cusped two power-law mass
distributions are relatively simple, and allow a very fast calculation even for
a chosen small fractional calculational error (e.g. $10^{-5}$). These results
will be particularly useful for studying lensed systems which provide a number
of accurate lensing constraints and for systematic analyses of large numbers of
lenses. Subroutines employing these results for the two power-law model and the
results by Chae, Khersonsky, & Turnshek for the generalized single power-law
mass model are made publicly available.
