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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | -2 |
| 3 | 6 |
| 4 | -22 |
| 5 | 90 |
| 6 | -394 |
| 7 | 1806 |
| 8 | -8558 |
| 9 | 41586 |
| 10 | -206098 |
| 11 | 1037718 |
| 12 | -5293446 |
| 13 | 27297738 |
| 14 | -142078746 |
| 15 | 745387038 |
| 16 | -3937603038 |
| 17 | 20927156706 |
| 18 | -111818026018 |
| 19 | 600318853926 |
| 20 | -3236724317174 |
| 21 | 17518619320890 |
| 22 | -95149655201962 |
| 23 | 518431875418926 |
| 24 | -2832923350929742 |
| 25 | 15521467648875090 |
[1,2,-2,6,-22,90,-394,1806,-8558,41586,-206098, 1037718,-5293446,27297738,-142078746,745387038, -3937603038,20927156706,-111818026018, 600318853926,-3236724317174,17518619320890, -95149655201962,518431875418926,-2832923350929742, 15521467648875090] |