@Test
    public void doTest() {
        fillIn();
        for (BigInteger b : trian) {
            for (BigInteger p : trian) {
                if (trian.contains(p.subtract(b).abs()) && trian.contains(p.add(b))) {
                    System.out.println(p + " " + b + " " + p.subtract(b).abs());
                }
            }
        }
    }