| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 5 |
| 4 | -12 |
| 5 | 89 |
| 6 | -345 |
| 7 | 3093 |
| 8 | -17136 |
| 9 | 178065 |
| 10 | -1313865 |
| 11 | 15537125 |
| 12 | -145520364 |
| 13 | 1937055977 |
| 14 | -22215578385 |
| 15 | 330407321013 |
| 16 | -4508998213440 |
| 17 | 74499864979361 |
| 18 | -1181547581150961 |
| 19 | 21576252384049093 |
| 20 | -389965846387214380 |
[0,1,-1,5,-12,89,-345,3093,-17136,178065,-1313865, 15537125,-145520364,1937055977,-22215578385, 330407321013,-4508998213440,74499864979361, -1181547581150961,21576252384049093, -389965846387214380] |