(algorithm)

**Definition:**
A class of *algorithms* that are *pseudo-random number generators*. The next number is generated from the current one by r_{n+1} = (A × r_{n} + B) mod M, where A and M are relatively prime numbers.

**Generalization** (I am a kind of ...)

*pseudo-random number generator*.

*Note:
When implemented in software, A and B may be chosen so as to have integer overflow on nearly every step, and therefore have a less predictable sequence and avoid the mod operation. The low-order bits tend to be less random than high-order bits. This is improved by discarding some of the low-order bits. Therefore, the range of random numbers is less than the range of the integer used in the computation. *

* Better algorithms are available, but they are more complex.*

Author: BB

Go to the Dictionary of Algorithms and Data Structures home page.

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Entry modified 26 July 2021.

HTML page formatted Mon Jul 26 11:58:06 2021.

Cite this as:

Bob Bockholt, "linear congruential generator", in
*Dictionary of Algorithms and Data Structures* [online], Paul E. Black, ed. 26 July 2021. (accessed TODAY)
Available from: https://www.nist.gov/dads/HTML/linearCongruentGen.html