I've complied a chart that can be used as a "general guideline" in figuring out how many shots required to shot a full 360 degree panorama. The chart assumes approximately 25% overlap. There is a bit of flexibility in selecting the correct click stop intervals especially at higher focal lengths. You could use the next higher or next lower click stop.
Fanotec's Advanced Rotator D-16 for example is capable of stops as small as 3.75 degrees - the smallest of any rotator on the market today.
see also: http://www.nodalninja.com/pano_calculations.html