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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -7 |
| 5 | 107 |
| 6 | -199 |
| 7 | 6031 |
| 8 | -5741 |
| 9 | 1129981 |
| 10 | -435569 |
| 11 | 35661419 |
| 12 | -1523489833 |
| 13 | 45183033541 |
| 14 | -12597680311 |
| 15 | 19055094997949 |
| 16 | -9331210633373 |
| 17 | 104148936040729 |
| 18 | -2250170748719203 |
| 19 | 734854328394419537 |
| 20 | -826511503463860961 |
[1,-1,1,-7,107,-199,6031,-5741,1129981,-435569, 35661419,-1523489833,45183033541,-12597680311, 19055094997949,-9331210633373,104148936040729, -2250170748719203,734854328394419537, -826511503463860961] |