Sobol algorithm creates sequences of "n-tuples" that fill the "n-space" more uniformly than random sequence. This type of sequence are called quasi-random sequences. That term is somewhat of a misnomer, since there is nothing random in this algorithm.
The experiments in this type of sequence are maximally avoiding of each other, filling in a uniform manner the design space.
This algorithm works best with 2 to 20 input variables and it is generally preferable to the "Random Sequence". The user must only specify the "Number of Designs" he wants to create, this number is limited to 64000.