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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 0 |
| 3 | 0 |
| 4 | -1 |
| 5 | 1 |
| 6 | -4 |
| 7 | -4 |
| 8 | -15 |
| 9 | -5 |
| 10 | -158 |
| 11 | 234 |
| 12 | -1349 |
| 13 | 2713 |
| 14 | -13704 |
| 15 | 42676 |
| 16 | -172825 |
| 17 | 559053 |
| 18 | -2029776 |
| 19 | 6774936 |
| 20 | -23900386 |
| 21 | 81129962 |
| 22 | -282099620 |
| 23 | 963894132 |
| 24 | -3331512669 |
| 25 | 11422580633 |
| 26 | -39350336472 |
| 27 | 134939821080 |
| 28 | -463383554563 |
| 29 | 1586767676943 |
| 30 | -5434335886108 |
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