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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | -35 |
| 3 | 259 |
| 4 | -1799 |
| 5 | 12607 |
| 6 | -88235 |
| 7 | 617659 |
| 8 | -4323599 |
| 9 | 30265207 |
| 10 | -211856435 |
| 11 | 1482995059 |
| 12 | -10380965399 |
| 13 | 72666757807 |
| 14 | -508667304635 |
| 15 | 3560671132459 |
| 16 | -24924697927199 |
| 17 | 174472885490407 |
| 18 | -1221310198432835 |
| 19 | 8549171389029859 |
[1,7,-35,259,-1799,12607,-88235,617659,-4323599, 30265207,-211856435,1482995059,-10380965399, 72666757807,-508667304635,3560671132459, -24924697927199,174472885490407,-1221310198432835, 8549171389029859] |