三角形开始:
1;
1, 2;
1, 2, 3;
2, 3, 4, 5;
3, 4, 5, 6, 7;
6, 7, 8, 9, 10, 11;
7, 8, 9, 10, 11, 12, 13;
10, 11, 12, 13, 14, 15, 16, 17;
11, 12, 13, 14, 15, 16, 17, 18, 19;
14, 15, 16, 17, 18, 19, 20, 21, 22, 23;
19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29;
20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31;
(结束)