How to Prevent CD4017 from Resetting to Random Count on Power On
The best (and most bulletproof) solution is to use a reset chip such as an ADM810. Suitable voltage ranges are available for 3.3V and 5V rails. If you have a different supply you may have to use a different supervisory chip that has resistor-programmable voltages. The below shows the functionality (the ADM810 has active-high output rather than the more commonly required active low shown in the diagram): 



When the voltage level drops below the lower threshold the reset signal is asserted for a minimum of 0.24 second. It is not released until the supply voltage is higher than the upper threshold for a minimum of 0.24 second. You should pick threshold voltages that guarantee proper operation at the lower threshold meaning it will operate down to the lower threshold and will always be reset properly. 

You may also need to put some resistance across the power supply to cause it to reset reasonably quickly rather than retain the previous state. Sometimes a fancier kind of clamp is used in special situations. 

The R-C kind of reset is sometimes used in low end consumer products where it's acceptable for it to fail once in a while (the user will just manually cycle the power), but it's a very poor substitute for a proper circuit.