public int getListSize(int number) {
        long target = number;

        int sequenceSize = 1;
        while (target != 1) {
            if (hailstoneSequenceSizeList.containsKey(target)) {
                sequenceSize = hailstoneSequenceSizeList.get(target) + sequenceSize;
                break;
            } else {
                if (target % 2 == 0)
                    target = target / 2;
                else
                    target = target * 3 + 1;

                sequenceSize +=1;
            }
        }

        hailstoneSequenceSizeList.put(number, sequenceSize);

        return sequenceSize;
    }