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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | -18 |
| 3 | 180 |
| 4 | -2187 |
| 5 | 29484 |
| 6 | -424116 |
| 7 | 6377292 |
| 8 | -99034650 |
| 9 | 1576075644 |
| 10 | -25569752274 |
| 11 | 421325812440 |
| 12 | -7031733125508 |
| 13 | 118620405322020 |
| 14 | -2019349799669160 |
| 15 | 34647126360607440 |
| 16 | -598525520999144643 |
| 17 | 10401492640172342940 |
| 18 | -181721630178565389900 |
| 19 | 3189811189331825319492 |
[1,3,-18,180,-2187,29484,-424116,6377292, -99034650,1576075644,-25569752274,421325812440, -7031733125508,118620405322020,-2019349799669160, 34647126360607440,-598525520999144643, 10401492640172342940,-181721630178565389900, 3189811189331825319492] |