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 | 3 |
| 5 | -40 |
| 6 | 250 |
| 7 | -1008 |
| 8 | 6517 |
| 9 | -87120 |
| 10 | 981924 |
| 11 | -9387840 |
| 12 | 103808727 |
| 13 | -1434810936 |
| 14 | 20930063102 |
| 15 | -308368386480 |
| 16 | 4838631496873 |
| 17 | -82524970065824 |
| 18 | 1497919608463368 |
| 19 | -28494789851849472 |
| 20 | 568078461069883755 |
[1,0,0,0,3,-40,250,-1008,6517,-87120,981924, -9387840,103808727,-1434810936,20930063102, -308368386480,4838631496873,-82524970065824, 1497919608463368,-28494789851849472, 568078461069883755] |