WithoutThreads

import java.util.*;

public class Main {

    public static void main(String[] args) {
        Date d1 = new Date();
        CounterClass c1 = new CounterClass(10000000, 40000000);
        while (true){
            if(!c1.getTh().isAlive()){
                System.out.println("Длина списка: " + c1.getList().size());
                Date d2 = new Date();
                long time = d2.getTime() - d1.getTime();
                System.out.println("Время выполнения: " + time + " мс"); //у меня ~700 мс
                break;
            }
        }
    }
}

public class CounterClass implements Runnable {
    private int beginIndex;
    private int endIndex;
    private ArrayList<Integer> list = new ArrayList<>();
    private Thread th;

    public CounterClass(int beginIndex, int endIndex) {
        this.beginIndex = beginIndex;
        this.endIndex = endIndex;
        th = new Thread(this);
        th.start();
    }

    @Override
    public void run() {
        for(int i = beginIndex; i <= endIndex; i++){
            if(i % 11 == 0 || i % 13 == 0 || i % 17 == 0) list.add(i);
        }
    }

    public Thread getTh() {
        return th;
    }

    public ArrayList<Integer> getList() {
        return list;
    }
}