Is it possible to calculate the difficulty purely by the number of blocks generated in e.g. 3 month and the staring difficulty? The background of this question is wether the distribution of the block generation does matter? Lets say we have a period of 12 weeks. If the number of blocks created in this time is 6*2016 then the difficulty should not change. If the number of blocks is (6*2016)*1,1 (10% more) the difficulty what have risen 6 times by 10%. This both statements should be true if the generation of the blocks is (more or less) equally distributed over the time.

I wonder now if this is true for different distributions.

I know there are this limits in difficulty adjustment (4 and 1/4) but if they are not reached it should be possible?
You should know the current difficulty to adjust the next value.
It can not be found only by number of blocks for past 3 monthes