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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | -5 |
| 3 | 23 |
| 4 | 205 |
| 5 | -1681 |
| 6 | -22265 |
| 7 | 257543 |
| 8 | 4544185 |
| 9 | -67637281 |
| 10 | -1491632525 |
| 11 | 27138236663 |
| 12 | 718181418565 |
| 13 | -15442193173681 |
| 14 | -476768795646785 |
| 15 | 11828536957233383 |
| 16 | 417370516232719345 |
| 17 | -11735529528739490881 |
| 18 | -465849831125196593045 |
| 19 | 14639678925928297567703 |
[1,-1,-5,23,205,-1681,-22265,257543,4544185, -67637281,-1491632525,27138236663,718181418565, -15442193173681,-476768795646785, 11828536957233383,417370516232719345, -11735529528739490881,-465849831125196593045, 14639678925928297567703] |