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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 22 |
| 6 | 255 |
| 7 | 3321 |
| 8 | 52948 |
| 9 | 1064988 |
| 10 | 25071525 |
| 11 | 667694395 |
| 12 | 20114706546 |
| 13 | 678833013618 |
| 14 | 25302305856919 |
| 15 | 1033146095157645 |
| 16 | 45956558123679960 |
| 17 | 2213869047416018296 |
| 18 | 114892917344393371209 |
| 19 | 6396625360877830999983 |
[1,3,22,255,3321,52948,1064988,25071525,667694395, 20114706546,678833013618,25302305856919, 1033146095157645,45956558123679960, 2213869047416018296,114892917344393371209, 6396625360877830999983] |