random

random

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

 

A linear congruential generator (LCG) is an algorithm that yields a sequence of pseudo-randomized numbers calculated with a discontinuous piecewise linear equation. The method represents one of the oldest and best-known pseudorandom number generatoralgorithms.^[1] The theory behind them is relatively easy to understand, and they are easily implemented and fast, especially on computer hardware which can provide modulo arithmetic by storage-bit truncation.

 

the "seed" or "start value"

Period length

The period of a general mixed congruential generator is at most m, and for some choices of factor a much less than that. The mixed congruential generator will have a full period for all seed values if and only if:

These three requirements are referred to as the Hull-Dobell Theorem.^[3][4]