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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 0 |
| 4 | -6 |
| 5 | 35 |
| 6 | -195 |
| 7 | 1358 |
| 8 | -10892 |
| 9 | 98037 |
| 10 | -980325 |
| 11 | 10783564 |
| 12 | -129402834 |
| 13 | 1682236855 |
| 14 | -23551315879 |
| 15 | 353269738170 |
| 16 | -5652315810840 |
| 17 | 96089368784297 |
| 18 | -1729608638117193 |
| 19 | 32862564124226648 |
| 20 | -657251282484533150 |
[0,1,-1,0,-6,35,-195,1358,-10892,98037,-980325, 10783564,-129402834,1682236855,-23551315879, 353269738170,-5652315810840,96089368784297, -1729608638117193,32862564124226648, -657251282484533150] |