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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -1 |
| 3 | 3 |
| 4 | -2 |
| 5 | -20 |
| 6 | 74 |
| 7 | 98 |
| 8 | -1532 |
| 9 | 960 |
| 10 | 41324 |
| 11 | -105732 |
| 12 | -1595912 |
| 13 | 7998640 |
| 14 | 85401224 |
| 15 | -705417112 |
| 16 | -6026865392 |
| 17 | 76352075520 |
| 18 | 537223559024 |
| 19 | -10130428275792 |
| 20 | -58185728893472 |
| 21 | 1628892022801600 |
| 22 | 7352490891960224 |
| 23 | -313251680404802272 |
[1,0,-1,3,-2,-20,74,98,-1532,960,41324,-105732, -1595912,7998640,85401224,-705417112,-6026865392, 76352075520,537223559024,-10130428275792, -58185728893472,1628892022801600,7352490891960224, -313251680404802272] |