  SU(3) gauge theory in the 2-index symmetric (sextet) and fundamental
representations is considered in symmetric and periodic boxes. Using the
overlap formulation in the quenched approximation it is shown that the
topological charge obtained from the sextet index theorem always leads to an
integer value and agrees with the charge obtained from the fundamental index
theorem in the continuum. At larger lattice spacing configurations exist with
fractional topological charge if the sextet index is used but these are lattice
artifacts and the probability of finding such a configuration rapidly
approaches zero. By considering the decomposition of the sextet representation
with respect to an SU(2) subgroup it is shown that the SU(2) adjoint index
theorem leads to integer charge as well. We conclude that the non-zero value of
the bilinear gaugino condensate in N=1 super-Yang-Mills theory cannot be
attributed to configurations with fractional topological charge once periodic
boundary conditions are imposed.
