Two methods to obtain numbers of stereoisomers and of achiral stereoisomers of a given molecular structure
are detailed on the example of di- and triinositols. The first method is manual exhaustive construction free
of redundance of all stereoisomers, which is rendered feasible by symmetry considerations despite the large
number of isomeric triinositols (82176). The second method is counting without constructing, made possible
by use of a mathematical tool, the Cauchy-Frobenius lemma, which actually is a formalized manner of
considering symmetry. The results are compared to those obtained by computer-aided stereoisomer generation
using the program MOLGEN 3.5. It is demonstrated that in their results all three methods agree.