The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | -640 |
| 3 | -55050240 |
| 4 | 2678771102515200 |
| 5 | 138029104604220676374528000 |
| 6 | -12755118515091679234002154772496384000000 |
| 7 | -3319735985081076411622842555075338617937492705280000000000 |
[1,2,-640,-55050240,2678771102515200, 138029104604220676374528000, -12755118515091679234002154772496384000000, -3319735985081076411622842555075338617937492705280\ 000000000] |