We present exact calculations of the zero-temperature partition function of
the q-state Potts antiferromagnet (equivalently the chromatic polynomial) for
Moebius strips, with width Ly​=2 or 3, of regular lattices and homeomorphic
expansions thereof. These are compared with the corresponding partition
functions for strip graphs with (untwisted) periodic longitudinal boundary
conditions.Comment: 9 pages, Latex, Phys. Lett. A, in pres