How to implement bezier curves for 3,4,5 points when there are 6?

Question

Java

There is a code for 6 Bizier points, what to change so that you can implement the same thing for 3,4,5 points. That is, use the same code, only for fewer points.

Bizje.java

import javax.swing.JFrame;
import javax.swing.JPanel;
import static javax.swing.JFrame.EXIT_ON_CLOSE;

import java.awt.Graphics;

public class Bizje extends JPanel {
  Coordinates[] points;
  Bizje(Coordinates[] points){
    this.points = points;
  }
  public static void bezier6(Coordinates[] points,Graphics g) {
    double t = 0.2, ts = 0.01;
    
    while(t <= 1) {
      double bn[] = {
/*1*/		-Math.pow((t-1), 5),
/*2*/		5 * t * Math.pow(((1-t)), 4),
/*3*/		-10 * Math.pow((t),2)*Math.pow((1-t), 3),
/*4*/		10 * Math.pow((t),3)*Math.pow((1-t), 2),
/*5*/		-Math.pow((t),4)*(-5 + 5*t),
/*6*/		Math.pow((t), 5)
      };
      double x = 0,y = 0;
      for (int i =0; i < points.length; i++) {
        x += points[i].x * bn[i];
        y += points[i].y * bn[i];
      }
      g.drawRect((int) x,(int) y, 1, 1);
      t += ts;
    }
  }

  
  public static void main(String[] args) {
    Coordinates []points = {new Coordinates(2,5),
        new Coordinates(6, 1),
        new Coordinates(8, 3),
        new Coordinates(13, 12),
        new Coordinates(21, 10),
        new Coordinates(27, 21)
      };

    
    JFrame window = new JFrame("Brez");
        window.setSize(100,100);
        window.setContentPane(new Bizje(points));
        window.setDefaultCloseOperation(EXIT_ON_CLOSE);
        window.setVisible(true);	
  }
  public void paintComponent(Graphics g){
        super.paintComponents(g);
     
       
    
    /*
     * Coordinates []points = {new Coordinates(2,5), new Coordinates(6,1), new
     * Coordinates(2,3), new Coordinates(13,12), new Coordinates(21,10), new
     * Coordinates(27,21) };
     */
 
    	 bezier6(points,g);
  }
  
}

coordinates.java

public class Coordinates {
  int x,y;
  Coordinates(int x, int y){
    this.x = x;
    this.y = y;
  }
}