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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | -4 |
| 5 | -1 |
| 6 | -69 |
| 7 | 321 |
| 8 | -1744 |
| 9 | 17289 |
| 10 | -151169 |
| 11 | 1476925 |
| 12 | -16575340 |
| 13 | 199103189 |
| 14 | -2588516917 |
| 15 | 36353994873 |
| 16 | -546329845632 |
| 17 | 8754613833201 |
| 18 | -149061793849185 |
| 19 | 2686816882818229 |
| 20 | -51112881539898028 |
| 21 | 1023425692313274509 |
[0,1,1,2,-4,-1,-69,321,-1744,17289,-151169, 1476925,-16575340,199103189,-2588516917, 36353994873,-546329845632,8754613833201, -149061793849185,2686816882818229, -51112881539898028,1023425692313274509] |