n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 36 |
5 | 240 |
6 | 2040 |
7 | 21000 |
8 | 235200 |
9 | 3265920 |
10 | 47628000 |
11 | 795175920 |
12 | 14411295360 |
13 | 279281882880 |
14 | 6049083680640 |
15 | 135398783520000 |
16 | 3367873821312000 |
17 | 87219462185856000 |
18 | 2403098895060864000 |
19 | 70681813184753971200 |
20 | 2138850761148310809600 |
[1,1,2,6,36,240,2040,21000,235200,3265920, 47628000,795175920,14411295360,279281882880, 6049083680640,135398783520000,3367873821312000, 87219462185856000,2403098895060864000, 70681813184753971200,2138850761148310809600] |