阵列开始于:
1, 1, 1, 1, 1, 1, 1, ...
1, 1, 2, 5, 14, 42, 132, ...
1, 1, 3, 14, 84, 594, 4719, ...
1, 1, 4, 30, 330, 4719, 81796, ...
1, 1, 5, 55, 1001, 26026, 884884, ...
1, 1, 6, 91, 2548, 111384, 6852768, ...
1, 1, 7, 140, 5712, 395352, 41314284, ...
...