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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 80 |
| 4 | 872 |
| 5 | 11984 |
| 6 | 198416 |
| 7 | 3840192 |
| 8 | 85031040 |
| 9 | 2119385856 |
| 10 | 58714881792 |
| 11 | 1789646610432 |
| 12 | 59515302478848 |
| 13 | 2144299161348096 |
| 14 | 83204666280609792 |
| 15 | 3459286210445942784 |
| 16 | 153413140701637804032 |
| 17 | 7228914528043587796992 |
| 18 | 360670654712328998289408 |
[1,2,10,80,872,11984,198416,3840192,85031040, 2119385856,58714881792,1789646610432, 59515302478848,2144299161348096,83204666280609792, 3459286210445942784,153413140701637804032, 7228914528043587796992,360670654712328998289408] |