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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | -6 |
| 4 | -36 |
| 5 | -270 |
| 6 | -1620 |
| 7 | -8526 |
| 8 | -41076 |
| 9 | -549870 |
| 10 | -13520340 |
| 11 | -262959246 |
| 12 | -3587233716 |
| 13 | -22581847470 |
| 14 | 584571618540 |
| 15 | 30096769542834 |
| 16 | 859315925548044 |
| 17 | 18434866643574930 |
| 18 | 285138881159407020 |
| 19 | 2045091797042889714 |
| 20 | -28367019385288799796 |
| 21 | 379914681728984325330 |
[1,0,0,-6,-36,-270,-1620,-8526,-41076,-549870, -13520340,-262959246,-3587233716,-22581847470, 584571618540,30096769542834,859315925548044, 18434866643574930,285138881159407020, 2045091797042889714,-28367019385288799796, 379914681728984325330] |