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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 49 |
| 5 | 380 |
| 6 | 3400 |
| 7 | 33469 |
| 8 | 352763 |
| 9 | 3914105 |
| 10 | 45203847 |
| 11 | 539095203 |
| 12 | 6600723606 |
| 13 | 82616454685 |
| 14 | 1053503618516 |
| 15 | 13650703465841 |
| 16 | 179351890161617 |
| 17 | 2385294488375623 |
| 18 | 32066177447127597 |
| 19 | 435218601202213040 |
[1,1,2,8,49,380,3400,33469,352763,3914105, 45203847,539095203,6600723606,82616454685, 1053503618516,13650703465841,179351890161617, 2385294488375623,32066177447127597, 435218601202213040] |