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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | -5 |
| 4 | 11 |
| 5 | 95 |
| 6 | -319 |
| 7 | -3895 |
| 8 | 17545 |
| 9 | 276545 |
| 10 | -1561505 |
| 11 | -30143405 |
| 12 | 204557155 |
| 13 | 4672227775 |
| 14 | -37024845055 |
| 15 | -976495604975 |
| 16 | 8848937968145 |
| 17 | 264630308948225 |
| 18 | -2698926080284225 |
| 19 | -90238935351344725 |
| 20 | 1022892984427721275 |
| 21 | 37810113912213439775 |
| 22 | -471553665821179507775 |
[1,1,-1,-5,11,95,-319,-3895,17545,276545,-1561505, -30143405,204557155,4672227775,-37024845055, -976495604975,8848937968145,264630308948225, -2698926080284225,-90238935351344725, 1022892984427721275,37810113912213439775, -471553665821179507775] |