Linear Congruential Generator is most common and oldest algorithm for generating pseudo-randomized numbers.

The generator is defined by the recurrence relation:

Xn+1 = (aXn + c) mod c

NOTE: where

• X is the sequence of pseudo-random values.
• m, 0< m- modulus.
• a, 0< a <m- multiplier.
• c, 0< = c<m- increment.
• x0, 0⇐x0<m- the seed or start value.

The next random integer is generated using the previous random integer, the integer constants, and the integer modulus.

• To get started, the algorithm requires an initial Seed, which must be provided by some means.
• The appearance of randomness is provided by performing modulo arithmetic.

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