This is a Lehmer PRNG, using the constants proposed by D. H. Lehmer in 1949. This implementation of the generator uses 64-bit integers, which may explain some of the issues that are presented in the tests below.

Of particular note, this generator performed very poorly in the Plot test, showing a very limited range of possible outputs.

// The current state value
state = 1138;

// Our constants
a = 16807
M = 2147483647

// random number generator
function RandomNumber() {

	// Run the function
	state = (a * state) % M;

	// Return the new value
	return state;

}