Turboprop vs Turbofan: How to compare Specific Fuel Consumption
Well, propellers deliver thrust and turbofan engines deliver power to the fan axis, it is just a matter of choice.

Finding the thrust that a propeller generates at a specific airspeed and altitude, can be derived from the drag of the whole airframe in those conditions. Statistically, this sort of data can be found in reference books on pre-design of aeroplanes, such as Synthesis of Subsonic Airplane Design by E. Torenbeek. If we take a generalised approach:

$$D = C_D \cdot ½ \rho V^2 \cdot S \tag{1}$$
$$C_D = C_{D0} + \frac{{C_L}^2}{\pi A e} \tag{2}$$
$$C_L = \frac{2W}{\rho V^2 S} \tag{3}$$

So total drag follows from: 


design factors weight W, wing area S, wing aspect ratio A, Oswald factor e. 
environmental factors airspeed V and air density $\rho$


For the generalised $C_{D0}$ of aeroplanes, from Torenbeek page 149:


So you can use all of this to compute propeller aeroplane specific thrust. But the exercise will be futile, because:


The engine of a turbofan looks remarkably like that of a turboprop. In fact, they are both turbine engines, powered by the Brayton cycle. Similar size and design engines deliver very similar gas generator power to the [fan or prop] axis.
Turbofan engines tend to larger than turboprop ones, generating extra efficiency due to less boundary layer effect and more uniform internal flow.
Speed is of the essence: at turboprop speeds, turbofans are not very efficient. At turbofan speeds, turboprop cannot deliver enough thrust due to propeller tip drag divergence. 
Turbofans utilise more of the hot exhaust flow for thrust generation due to the higher required flight speed. Lower efficiency, higher thrust.