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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 88 |
| 6 | 252 |
| 7 | 2112 |
| 8 | 4224 |
| 9 | 8448 |
| 10 | 44544 |
| 11 | 48384 |
| 12 | 405504 |
| 13 | 4091904 |
| 14 | 405909504 |
| 15 | 677707776 |
| 16 | 4285005824 |
| 17 | 21128282112 |
| 18 | 29142024192 |
| 19 | 4815463645184 |
| 20 | 445488555884544 |
| 21 | 27874867776847872 |
| 22 | 40539458585493504 |
| 23 | 63556806860865536 |
| 24 | 840261068860162048 |
| 25 | 4870324782874230784 |
[1,2,4,8,88,252,2112,4224,8448,44544,48384,405504, 4091904,405909504,677707776,4285005824, 21128282112,29142024192,4815463645184, 445488555884544,27874867776847872, 40539458585493504,63556806860865536, 840261068860162048,4870324782874230784] |