How can I generate different random numbers using a seed with a loop? [duplicate]

This question already has an answer here:

• How do I compare strings in Java? 23 answers

I'm making a simple gradebook that's supposed to generate random numbers for each assignment for each student. It generates random numbers, but the numbers are the same each loop. Here's the code I have so far:

import java.util.Random;
import java.util.Scanner;

public class Testing {
public static void main(String args[]) {
    Scanner sc = new Scanner(System.in);
    String choice = "y";
    while (choice == "y")   { 

        System.out.println("Please enter a number for the random number generator seed:");
        //User input for seed
        int seed = sc.nextInt(); 
        //Initializing Seed
        Random randomSeed = new Random(seed);

        //Prompting for number of students
        System.out.println("Please enter the no of students for whom you have grade information: "); 
        //User input for number of students
        int numberOfStudents = sc.nextInt();

        String homework = "HW";

        System.out.printf("%16s", homework);
        System.out.println("\n");

        //Finding random value for Homework.
        int randomHomework = randomSeed.nextInt(((600-300) + 1) + 300); 

        //Creates an array that has 7 rows for points
        //Will eventually add more values into array
        int points [][] = new int[6][3]; 

        //for loop that starts at 1 and prints number of students user entered
        for (int i = 0; i < numberOfStudents; i++) {
            System.out.print("Student #" + (i + 1) + "    ");

            points[0][2] += randomHomework;
            System.out.print(randomHomework + "    ");

            System.out.println("\n");
            }//End of for loop

        choice = sc.nextLine().toUpperCase();
        }//End of while loop
    }
}

I get 540 points for each student, but I should be getting a random value between 300 and 600 for each student each time it loops.

Thanks for anything!