What is the transitive group details of a polynomial where only the third power terms occur? That is $x^{3n} + a_{n-1} x^{3(n-1)} + ... + a_1 x^3 + a_0$. I need the basic theorems that state or prove this group structure. I think that the answer is $C_{3} \wr {S}_{n}$ from other examples however I do not understand this answer well. Likewise I need the theorem for the quadratic case of just even powers occurring.
Thanks in advance!