n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 5 |
4 | 27 |
5 | 168 |
6 | 1200 |
7 | 9720 |
8 | 88200 |
9 | 887040 |
10 | 9797760 |
11 | 117936000 |
12 | 1536796800 |
13 | 21555072000 |
14 | 323805081600 |
15 | 5187108326400 |
16 | 88268019840000 |
17 | 1590132031488000 |
18 | 30233431388160000 |
19 | 605024315191296000 |
20 | 12711912992722944000 |
21 | 279783730940313600000 |
22 | 6437458713635389440000 |
[0,1,5,27,168,1200,9720,88200,887040,9797760, 117936000,1536796800,21555072000,323805081600, 5187108326400,88268019840000,1590132031488000, 30233431388160000,605024315191296000, 12711912992722944000,279783730940313600000, 6437458713635389440000] |