n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 2 |
4 | 3 |
5 | 4 |
6 | 20 |
7 | 216 |
8 | 1862 |
9 | 13840 |
10 | 104904 |
11 | 949200 |
12 | 10517232 |
13 | 130307904 |
14 | 1694503824 |
15 | 23063845728 |
16 | 335427395760 |
17 | 5269616092416 |
18 | 88835797577472 |
19 | 1587229554415104 |
20 | 29838489410093184 |
21 | 589394278657267200 |
22 | 12235109311726689024 |
23 | 266570965998899071488 |
[0,1,2,3,4,20,216,1862,13840,104904,949200, 10517232,130307904,1694503824,23063845728, 335427395760,5269616092416,88835797577472, 1587229554415104,29838489410093184, 589394278657267200,12235109311726689024, 266570965998899071488] |