n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 2 |
3 | 6 |
4 | 60 |
5 | 380 |
6 | 3990 |
7 | 37002 |
8 | 450296 |
9 | 5373720 |
10 | 76018410 |
11 | 1096730030 |
12 | 17814654132 |
13 | 299645294676 |
14 | 5511836578430 |
15 | 105550556136690 |
16 | 2171244984679920 |
17 | 46545825736022192 |
18 | 1059273836225051346 |
19 | 25100215228045842390 |
20 | 626204775725372971820 |
21 | 16239127347086448236460 |
[0,0,2,6,60,380,3990,37002,450296,5373720, 76018410,1096730030,17814654132,299645294676, 5511836578430,105550556136690,2171244984679920, 46545825736022192,1059273836225051346, 25100215228045842390,626204775725372971820, 16239127347086448236460] |