RLC circuit transfer functions
As I pointed out in the comments, the transfer function, defined as:
$$ TF(s) = \frac{V_o(s)}{V_i(s)}$$
is 1 on both circuits, regardless s.

If you cascade them, it is still 1.

Maybe you meant the admittance of the parallel, defined as:
$$Y(s)=\frac{I_i(s)}{V_i(s)}$$

Then it is the sum of the two admittances. The impedance is its reciprocal. 

The parallel equivalent circuit will have a resistor which is the parallel of the two resistors, a capacitor, which is the parallel of the two capacitors, and an inductor which is the parallel of the two inductors. Remmeber what happens when you put in parallel two inductors, two resistors and two capacitors.