private ArrayList<Integer> findNumbers(int[] sequenceOne, int[] sequenceTwo) {

        ArrayList<Integer> sequenceToReturn = new ArrayList<>();

        int counter;
        boolean primeFlag;

        for(int i : sequenceOne) {
            counter = 0;
            primeFlag = true;

            for(int j : sequenceTwo) {
                if(i == j)
                    counter++;
            }

            if(counter == 0 || counter == 1)
                primeFlag = false;
            else {
                for (int p = counter - 1; p > 1; p--) {
                    if (counter % p == 0) {
                        primeFlag = false;
                        break;
                    }
                }
            }

            if(!primeFlag)
                sequenceToReturn.add(i);

        }

        return sequenceToReturn;

    }