Random number generators

A random number generator is a computational program or physical device designed to generate a sequence of numbers that does not have any discernable pattern, so that the sequence can be treated as being random. Random number generators have existed since ancient times, in the form of dice and coin flipping, the shuffling of playing cards, the use of yarrow stalks in the I Ching, and many other methods. A "true" random number is often difficult to decide, since the concept of randomness is itself somewhat difficult to define. What is universally agreed is that any "random number generator" based solely on deterministic computation cannot be regarded as a "true" random number generator, since its output is inherently predictable.