Trying to create fractals images with particles, but getting weird pattern instead

I'm so close!

I'm trying to create fractal images with the following equation:http://glowingpython.blogspot.com/2013/07/hopalong-fractals.html. And it should look something like this but in 3D: http://2.bp.blogspot.com/-JPRMjjdIMng/Ud1cTJuRA7I/AAAAAAAAAps/l53raY926yA/s1600/hopalong_orbit.png

But I'm getting a very strange output: http://postimg.org/image/7jax5glup/ See the green particles are the 40 particles that are emitted. Even trying with 4000 or 400000 particles, it still forms a very similar shape.

This is my code: #pragma strict

function Start () { var myParticleSystem : ParticleSystem; var myParticles: ParticleSystem.Particle[];

 myParticleSystem = GetComponent( ParticleSystem );
 myParticleSystem.Emit(40);
 var num_particles = myParticleSystem.particleCount; 
 myParticles = new ParticleSystem.Particle[num_particles+1];


 var a = -55;
 var b = -1  ;
 var c = -42;

 var x : float; 
 var y : float; 
 var z : float; 

 var particlePosition : Vector3;

 for (var i = 0; i < num_particles; i++){ // Generalization of Barry Martin's original 
     particlePosition = myParticles[i].position;  
     x = Random.value * -1 ; 
     y = Random.value * 10;
     // HERE I FOLLOW THE EQUATION EXACTLY HOW IT'S GIVEN
 var x1 = y- x / Mathf.Abs(x) * Mathf.Sqrt(Mathf.Abs(b * x + c));
     var y1 = a - x;
     var newposition = new Vector3(x1,y1,Random.value);

     myParticleSystem.GetParticles(myParticles);         
     myParticles[i].position = newposition; 
     myParticleSystem.SetParticles(myParticles, num_particles);      
 }

}