The digit generating function of a polynomial

The average frequency of 1 occurring as the kth digit in the binary expansion of squares, cubes, and generally the values of a polynomial is studied. In particular, it turns out that the generating function of these frequencies is rational for the important special cases of powers, linear and quadratic polynomials. For higher degree polynomials, the behaviour seems to be much more chaotic in general, which is exhibited by two examples of cubic polynomials.