The RANDU linear congruential uniform random number generator was used in the 1960s. It has become infamous because when generated uniform values are used three at a time in a 3-tuple (tuplet), the generator is biased. When the 3-tuples are plotted, one can observe that they fall on one of 15 planes in three-dimensional space. As a result, the are highly correlated and biased in whatever context they are used.