What is "wichmann-hill"

Wichmann-Hill is a pseudorandom number generator proposed in 1982 by Brian Wichmann and David Hill. In its core, numbers are generated by taking the fractional part of a sum of rectangularly distributed numbers from imperfect algorithms. As the addition of fractional parts of numbers will be rectangularly distributed if only one of the number is rectangular, the method is an appropriate generator. In its crude form, three number generators are used to create a pseudorandom sequence with cycle exceeding 6.95 * 10. A brute-force computation result of AS183 shows that the length of cycle is 6953607871644.