The compound shown is 1,2,4-trimethylcyclohexane with no configuration specified. Treating the ring as planar and counting configurational stereoisomers only (all cis/trans arrangements and enantiomers), how many stereoisomers does it have? Give the answer as an integer.

C1, C2 and C4 are all stereocentres. Unlike 1,2,3- or 1,3,5-trimethylcyclohexane, the 1,2,4 pattern has no symmetry element that exchanges two methyl-bearing carbons: C1 is adjacent to C2 only, C2 is between C1 and C3, and C4 is separated from both. So no cis/trans arrangement can possess a mirror plane and no meso form exists. The count is the maximum, $2^3=8$, i.e. four pairs of enantiomers (confirmed by enumeration).