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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 4 |
| 4 | -14 |
| 5 | 60 |
| 6 | -376 |
| 7 | 2784 |
| 8 | -23344 |
| 9 | 225680 |
| 10 | -2467456 |
| 11 | 29884864 |
| 12 | -397908224 |
| 13 | 5784292800 |
| 14 | -91090625536 |
| 15 | 1544557830144 |
| 16 | -28061704443904 |
| 17 | 543835022577920 |
| 18 | -11198060484591616 |
| 19 | 244140571254682624 |
| 20 | -5618495694469136384 |
[0,1,-1,4,-14,60,-376,2784,-23344,225680,-2467456, 29884864,-397908224,5784292800,-91090625536, 1544557830144,-28061704443904,543835022577920, -11198060484591616,244140571254682624, -5618495694469136384] |