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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -3 |
| 3 | 18 |
| 4 | -145 |
| 5 | 1398 |
| 6 | -15330 |
| 7 | 186004 |
| 8 | -2455893 |
| 9 | 34903110 |
| 10 | -529903726 |
| 11 | 8547005820 |
| 12 | -145847288730 |
| 13 | 2624318836412 |
| 14 | -49658727391620 |
| 15 | 985921121129832 |
| 16 | -20496980960236365 |
| 17 | 445413655950148710 |
| 18 | -10100793273684125430 |
[1,1,-3,18,-145,1398,-15330,186004,-2455893, 34903110,-529903726,8547005820,-145847288730, 2624318836412,-49658727391620,985921121129832, -20496980960236365,445413655950148710, -10100793273684125430] |