MINSTD is a Lehmer generator found in the C++ standard. This uses the revised constants proposed by Park and Miller in the 1980s, along with a more complex implementation that avoids 64-bit mathematics.

These changes make quite a large difference, as this generator passes nearly every test. Even the Plot test shows a decent distribution of outputs, though it could be better.

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

			
// The current state value
state = 1138;

// Our constants
a = 16807;
M = 2147483647;
q = 127773;
r = 2836;

// random number generator
function RandomNumber() {

	// Save the state
	x = state;

	// Run the math
	h = int( x / q );
	t = a * (x - (h * q)) - (h * r);

	if (t < 0) {
		t = t + M;
	}
	
	// Save the new value
	state = t;
	
	// And return it
	return state;

}