The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | -12 |
| 5 | 120 |
| 6 | -1020 |
| 7 | 8820 |
| 8 | -79548 |
| 9 | 746928 |
| 10 | -7222560 |
| 11 | 70422000 |
| 12 | -663291552 |
| 13 | 5383325376 |
| 14 | -19385922192 |
| 15 | -677619961200 |
| 16 | 27837247597392 |
| 17 | -777514428757632 |
| 18 | 19561790897109504 |
| 19 | -475628128967428992 |
| 20 | 11488209552378045888 |
[1,0,0,0,-12,120,-1020,8820,-79548,746928, -7222560,70422000,-663291552,5383325376, -19385922192,-677619961200,27837247597392, -777514428757632,19561790897109504, -475628128967428992,11488209552378045888] |