The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 2 |
| 4 | 7 |
| 5 | 32 |
| 6 | 112 |
| 7 | 10800 |
| 8 | 403200 |
| 9 | 17418254400 |
| 10 | 1755760043520000 |
[0,1,6,2,7,32,112,10800,403200,17418254400, 1755760043520000] |