三角形开始
.n\k.|。。0.....1.....2.....3.....4.....5.....6
= = = = = = = = = = = = = = = = = = = = = = =
..0..|..0
..1..|..1.....0
..2..|..2.....2.....0
..3..|..3.....6.....3.....0
..4..|..4....12....12.....4.....0
..5..|。。5....20....30....20.....5.....0
..6..|..6….30….60….60….30….6….0
...
|