RANDU was a popular Lehmer generator. Once the flaws in its output became widely known, it was abandoned in favor of more reliable generators.

The biggest flaw with this generator is that the output tends to cluster in groups, as clearly evidenced by the lower resolution Plot test result. A 3D spetrum plot, which is not part of our tests, would make the output groupings extremely noticable.

// This code is adapted from RANDU's implementation
// in the GNU Scientific Library.
//
// https://www.gnu.org/software/gsl/

			
// The current state value
state = 1138;

// Our constants
a = 65539;
M = 2147483647;

// random number generator
function RandomNumber() {

	// Run the math
	state := (a * state) % M;
	
	// And return it
	return state;

}