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| n | a(n) |
|---|---|
| 10 | 28 |
| 11 | 1468 |
| 12 | 34680 |
| 13 | 535452 |
| 14 | 6302296 |
| 15 | 61400920 |
| 16 | 520788460 |
| 17 | 3976323744 |
| 18 | 27974148068 |
| 19 | 184411212644 |
| 20 | 1153389882896 |
| 21 | 6908837566500 |
| 22 | 39921952365008 |
[28,1468,34680,535452,6302296,61400920,520788460, 3976323744,27974148068,184411212644,1153389882896, 6908837566500,39921952365008] |