CycleIndexPolynomial
CycleIndexPolynomial[perm, {x1, ..., xn}] constructs the cycle index monomial of the permutation perm in the variables xi.
CycleIndexPolynomial[group, {x1, ..., xn}] constructs the cycle index polynomial of group in the variables xi.
Examples
Cycle index of a permutation:
CycleIndexPolynomial[Cycles[{{1, 2, 3}}], {x1, x2, x3}]
(* x3 *)For a symmetric group:
CycleIndexPolynomial[SymmetricGroup[3], {x1, x2, x3}]Please visit the official Wolfram Language Reference for more details.