Figure: 
: A eight cell cycle repeated twice to get sixteen
cells.
Any cycle of length N is automatically a cycle of length 2N; or of
any other integer multiple kN for that matter. Consequently censuses
are prone to containing divisors unless it is agreed that they should be
omitted from the tally, just as it is usually agreed to drop quiescent
configurations (which are really just a special case). Figure 
shows the cycle of period six which can also be found in rings of
length eight.