| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 4 |
| 4 | -6 |
| 5 | 5 |
| 6 | 195 |
| 7 | -2704 |
| 8 | 29652 |
| 9 | -331843 |
| 10 | 3601035 |
| 11 | -41849436 |
| 12 | 488807814 |
| 13 | -6056793535 |
| 14 | 75941139183 |
| 15 | -991400372208 |
| 16 | 12952602361800 |
| 17 | -170364782863687 |
| 18 | 2130756803110071 |
| 19 | -23615067306171612 |
| 20 | 149846016306473010 |
[0,1,-1,4,-6,5,195,-2704,29652,-331843,3601035, -41849436,488807814,-6056793535,75941139183, -991400372208,12952602361800,-170364782863687, 2130756803110071,-23615067306171612, 149846016306473010] |