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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 11 |
| 6 | 23 |
| 7 | 52 |
| 8 | 120 |
| 9 | 247 |
| 10 | 534 |
| 11 | 1433 |
| 12 | 2540 |
| 13 | 3264 |
| 14 | 30169 |
| 15 | 19123 |
| 16 | -363258 |
| 17 | 2951500 |
| 18 | -1601367 |
| 19 | -99325484 |
| 20 | 799655132 |
| 21 | -1194225728 |
| 22 | -32599353806 |
| 23 | 345568196667 |
| 24 | -1063427879019 |
| 25 | -13137091603516 |
| 26 | 205598895773140 |
| 27 | -1103275663780401 |
[1,1,2,5,11,23,52,120,247,534,1433,2540,3264, 30169,19123,-363258,2951500,-1601367,-99325484, 799655132,-1194225728,-32599353806,345568196667, -1063427879019,-13137091603516,205598895773140, -1103275663780401] |