  The method of Jain and Kamilla [PRB {\bf 55}, R4895 (1997)] allows numerical
generation of composite fermion trial wavefunctions for large numbers of
electrons in high magnetic fields at filling fractions of the form nu=p/(2mp+1)
with m and p positive integers. In the current paper we generalize this method
to the case where the composite fermions are in an effective (mean) field with
opposite sign from the actual physical field, i.e. when p is negative. We
examine both the ground state energies and the low energy neutral excitation
spectra of these states. Using particle-hole symmetry we can confirm the
correctness of our method by comparing results for the series m=1 with p>0
(previously calculated by others) to our results for the conjugate series m=1
with p <0. Finally, we present similar results for ground state energies and
low energy neutral excitations for the states with m=2 and p <0 which were not
previously addressable, comparing our results to the m=1 case and the p > 0,
m=2 cases.
