66, 68, 76, 78, 88, 86, 96, 98, 666, 686, 668, 888, 866, 868, 886, 776, 778, 998, 996, 786, 766, 966, 986, 968, 768, 6666, 6668, 6688, 6686, 6868, 6886, 8888, 8686, 8886, 8866, 9998, 9988, 9986, 9686, 9888, 9666, 9866, 7888, 7666, 7868, 7886, 7866, 7778, 7786, 7996, 7966 etc.