n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 30 |
5 | 150 |
6 | 1020 |
7 | 7140 |
8 | 63420 |
9 | 611100 |
10 | 6625080 |
11 | 72875880 |
12 | 977213160 |
13 | 12876743880 |
14 | 190951160400 |
15 | 2975661889200 |
16 | 51767677962000 |
17 | 886225654314000 |
18 | 17136230971860000 |
19 | 329530590793404000 |
20 | 7035395004749311200 |
21 | 151961029211943151200 |
[1,1,2,6,30,150,1020,7140,63420,611100,6625080, 72875880,977213160,12876743880,190951160400, 2975661889200,51767677962000,886225654314000, 17136230971860000,329530590793404000, 7035395004749311200,151961029211943151200] |