Yep, that one DrStrange gist.

DrStrange.java

import java.util.ArrayList;
import java.util.List;

class DrStrange {


    private static List<Integer> numbers;

    public DrStrange() {
    numbers = new ArrayList<>(); }

    public void add(int number) {
        numbers.add(number); 
    }

    public int sum() {
        int sum = 0;
        for (int number : numbers) {
            sum += number;
        }
        return sum;
    }
    public static void main(String[] args) {
        DrStrange[] mysteries = new DrStrange[5];
        for (int i = 0; i < 25; i++) {
            int index = i / 5;
            if (i % 5 == 0) {
                mysteries[index] = new DrStrange();
            }
            mysteries[index].add(i);
        }
        for (int i = 0; i < mysteries.length; i++) {
            System.out.println(mysteries[i].sum());
        }

        for(DrStrange i : mysteries)
            System.out.println(i);
    }
}