Pseudo-random number

A pseudo-random number is a number belonging to a sequence which appears to be random, but can in fact be generated by a finite computation. They are used extensively in computer science in places where randomness is essential to some application, but cannot be generated due to computation being deterministic.

The qualities which are required of a pseudo-random sequence of (binary) digits -- if it is to be used in any application where apparent randomness is important -- are as follows:

• the 2ⁿ different patterns of n successive digits should each occur about as often as each other
• sequences of n(>1) 0s should occur about half as often as sequences of n-1 0s, and about as often as n 1s

Various examples of pseudorandom number generators exist, such as linear congruential generators, inversive generators etc.

See also

• Pseudorandom number generator

External links

• http://www.merrymeet.com/jon/usingrandom.html