The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -25 |
| 2 | 275 |
| 3 | -1750 |
| 4 | 7300 |
| 5 | -23255 |
| 6 | 73150 |
| 7 | -252625 |
| 8 | 796275 |
| 9 | -2137925 |
| 10 | 5733355 |
| 11 | -16646550 |
| 12 | 45304475 |
| 13 | -111461125 |
| 14 | 280683700 |
| 15 | -735052700 |
| 16 | 1815283450 |
| 17 | -4275549750 |
| 18 | 10301217900 |
| 19 | -24923579950 |
| 20 | 58128778485 |
| 21 | -133132664600 |
[1,-25,275,-1750,7300,-23255,73150,-252625,796275, -2137925,5733355,-16646550,45304475,-111461125, 280683700,-735052700,1815283450,-4275549750, 10301217900,-24923579950,58128778485, -133132664600] |