三角形开始:
[0] 1
[1] 1, 6
[2] 20, 60, 60
[3] 210, 420, 420, 210
[4] 1512, 2520, 2520, 1512, 504
[5] 9240, 13860, 13860, 9240, 3960, 990
[6] 51480, 72072, 72072, 51480, 25740, 8580, 1716
[7] 270270, 360360, 360360, 270270, 150150, 60060, 16380, 2730
[8] 1361360, 1750320, 1750320, 1361360, 816816, 371280, 123760, 28560, 4080