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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 5 |
| 3 | -5 |
| 4 | 109 |
| 5 | -497 |
| 6 | 127 |
| 7 | -11569 |
| 8 | 312757 |
| 9 | -1219255 |
| 10 | 165677473 |
| 11 | -885730939 |
| 12 | 20163875141 |
| 13 | -252312616027 |
| 14 | 9565074633871 |
| 15 | -691138954263097 |
| 16 | 5061676927076641 |
| 17 | -95993669516238563 |
| 18 | 1245671625068799013 |
[1,-1,5,-5,109,-497,127,-11569,312757,-1219255, 165677473,-885730939,20163875141,-252312616027, 9565074633871,-691138954263097,5061676927076641, -95993669516238563,1245671625068799013] |