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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | -4 |
| 4 | -5 |
| 5 | -21 |
| 6 | 59 |
| 7 | 184 |
| 8 | 1469 |
| 9 | -2515 |
| 10 | -44419 |
| 11 | -389004 |
| 12 | -677129 |
| 13 | 48209431 |
| 14 | 432521335 |
| 15 | 6727493744 |
| 16 | -202699840391 |
| 17 | -2757368732391 |
| 18 | -137883154808071 |
| 19 | 3024277973351020 |
| 20 | 134932587262253171 |
| 21 | 10064373238238267651 |
[1,1,1,-4,-5,-21,59,184,1469,-2515,-44419,-389004, -677129,48209431,432521335,6727493744, -202699840391,-2757368732391,-137883154808071, 3024277973351020,134932587262253171, 10064373238238267651] |