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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | -5 |
| 4 | 11 |
| 5 | 91 |
| 6 | -391 |
| 7 | -4115 |
| 8 | 27971 |
| 9 | 357331 |
| 10 | -3353731 |
| 11 | -50789375 |
| 12 | 607914581 |
| 13 | 10692083221 |
| 14 | -155442170521 |
| 15 | -3120028100285 |
| 16 | 53341649623091 |
| 17 | 1204301220497011 |
| 18 | -23663734574555011 |
| 19 | -593828627529030095 |
| 20 | 13182525824990398001 |
[1,1,-1,-5,11,91,-391,-4115,27971,357331,-3353731, -50789375,607914581,10692083221,-155442170521, -3120028100285,53341649623091,1204301220497011, -23663734574555011,-593828627529030095, 13182525824990398001] |