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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | -1 |
| 3 | 7 |
| 4 | -14 |
| 5 | 693 |
| 6 | -30030 |
| 7 | 4150146 |
| 8 | -21441420 |
| 9 | 3508377873 |
| 10 | -425496301230 |
| 11 | 163608770318994 |
| 12 | -381271515244620 |
| 13 | 263655717130655850 |
| 14 | -20916990073196036820 |
| 15 | 28579221265797444862620 |
| 16 | -20735968190374168899967800 |
| 17 | 535753174085515196009964765 |
| 18 | -2008476391973175078407803350 |
[0,0,-1,7,-14,693,-30030,4150146,-21441420, 3508377873,-425496301230,163608770318994, -381271515244620,263655717130655850, -20916990073196036820,28579221265797444862620, -20735968190374168899967800, 535753174085515196009964765, -2008476391973175078407803350] |