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| n | a(n) |
|---|---|
| 0 | -1 |
| 1 | 4 |
| 2 | 227 |
| 3 | 5329 |
| 4 | -26581 |
| 5 | 206116 |
| 6 | 2391479 |
| 7 | 16785409 |
| 8 | -174757993 |
| 9 | 2826198244 |
| 10 | 9824173259 |
| 11 | 14210785681 |
| 12 | -287742103741 |
| 13 | 22876687229764 |
| 14 | -22446053606113 |
| 15 | 89792737665409 |
| 16 | 5164999769137199 |
| 17 | 122161424469552196 |
| 18 | -606821408584323661 |
| 19 | 4689875711360495569 |
[-1,4,227,5329,-26581,206116,2391479,16785409, -174757993,2826198244,9824173259,14210785681, -287742103741,22876687229764,-22446053606113, 89792737665409,5164999769137199, 122161424469552196,-606821408584323661, 4689875711360495569] |