The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | -4 |
| 4 | 8 |
| 5 | -16 |
| 6 | 12 |
| 7 | -96 |
| 8 | -480 |
| 9 | -4672 |
| 10 | -45520 |
| 11 | -493120 |
| 12 | -5798912 |
| 13 | -73668608 |
| 14 | -1005335552 |
| 15 | -14671085568 |
| 16 | -228051746304 |
| 17 | -3762955404288 |
| 18 | -65707303602432 |
| 19 | -1210821292674048 |
| 20 | -23487031074109440 |
| 21 | -478463919131627520 |
| 22 | -10214440549929047040 |
| 23 | -228069193578011566080 |
[1,-4,8,-16,12,-96,-480,-4672,-45520,-493120, -5798912,-73668608,-1005335552,-14671085568, -228051746304,-3762955404288,-65707303602432, -1210821292674048,-23487031074109440, -478463919131627520,-10214440549929047040, -228069193578011566080] |