| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -2 |
| 3 | -18 |
| 4 | 1152 |
| 5 | 720000 |
| 6 | -5598720000 |
| 7 | -658683809280000 |
| 8 | 1381360067999170560000 |
| 9 | 59463021447701323327733760000 |
| 10 | -59463021447701323327733760000000000000 |
| 11 | -1542317635347398938581016812202229760000000000000 |
[1,1,-2,-18,1152,720000,-5598720000, -658683809280000,1381360067999170560000, 59463021447701323327733760000, -59463021447701323327733760000000000000, -1542317635347398938581016812202229760000000000000\ ] |