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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | -2 |
| 3 | 3 |
| 4 | -8 |
| 5 | 53 |
| 6 | -320 |
| 7 | 1799 |
| 8 | -14464 |
| 9 | 154985 |
| 10 | -1601152 |
| 11 | 16589771 |
| 12 | -211517440 |
| 13 | 3172731677 |
| 14 | -47440986112 |
| 15 | 721614303695 |
| 16 | -12501759557632 |
| 17 | 241340829836497 |
| 18 | -4730336839303168 |
| 19 | 94965599172723859 |
[0,1,-2,3,-8,53,-320,1799,-14464,154985,-1601152, 16589771,-211517440,3172731677,-47440986112, 721614303695,-12501759557632,241340829836497, -4730336839303168,94965599172723859] |