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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 2 |
| 3 | -2 |
| 4 | 8 |
| 5 | 8 |
| 6 | 112 |
| 7 | 656 |
| 8 | 5504 |
| 9 | 49024 |
| 10 | 491264 |
| 11 | 5401856 |
| 12 | 64826368 |
| 13 | 842734592 |
| 14 | 11798300672 |
| 15 | 176974477312 |
| 16 | 2831591702528 |
| 17 | 48137058811904 |
| 18 | 866467058876416 |
| 19 | 16462874118127616 |
| 20 | 329257482363600896 |
| 21 | 6914407129633521664 |
| 22 | 152116956851941670912 |
[1,-1,2,-2,8,8,112,656,5504,49024,491264,5401856, 64826368,842734592,11798300672,176974477312, 2831591702528,48137058811904,866467058876416, 16462874118127616,329257482363600896, 6914407129633521664,152116956851941670912] |