n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 30 |
6 | 120 |
7 | 1560 |
8 | 10920 |
9 | 185640 |
10 | 2042040 |
11 | 181741560 |
12 | 1090449360 |
13 | 254074700880 |
14 | 7368166325520 |
15 | 449458145856720 |
16 | 21124532855265840 |
17 | 33735878969859546480 |
18 | 640981700427331383120 |
19 | 2679944489486672512824720 |
20 | 109877724068953573025813520 |
[1,1,2,6,30,120,1560,10920,185640,2042040, 181741560,1090449360,254074700880,7368166325520, 449458145856720,21124532855265840, 33735878969859546480,640981700427331383120, 2679944489486672512824720, 109877724068953573025813520] |