class Rabbits {

	public static void main (String args[]) {
	
		int numberOfRabbits = 2;
		System.out.println("In generation 1 there are 2 rabbits.");
	
		for (int i = 2; i <= 20; i++) {
		
			numberOfRabbits = numberOfRabbits + (numberOfRabbits * 2) - numberOfRabbits;
			// Which is, of course, just numberOfRabbits * 2.
			System.out.println("In generation " + i + " there are " + numberOfRabbits + " rabbits.");
		
		}
		
	}
	
}