using Combinatorics
permutations(1:4) |> collect

using Permutations

for σ in PermGen(4)
    @show σ, (σ(1), σ(2), σ(3), σ(4)), σ.([1,2,3,4])
end

S4 = collect(PermGen(4))

σ = S4[3]

τ = S4[20]

σ*τ