Sobol sequence:quasi-random low-discrepancy sequences.

https://en.wikipedia.org/wiki/Sobol_sequence

https://medium.com/@antoine_savine/sobol-sequence-explained-188f422b246b

https://medium.com/@antoine_savine/sobol-sequence-explained-188f422b246b

https://math.stackexchange.com/questions/888490/understanding-sobol-sequences