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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 30 |
| 5 | 124 |
| 6 | 733 |
| 7 | 4586 |
| 8 | 33373 |
| 9 | 259434 |
| 10 | 2152298 |
| 11 | 18615182 |
| 12 | 166544071 |
| 13 | 1528659536 |
| 14 | 14328433429 |
| 15 | 136649176084 |
| 16 | 1322594487342 |
| 17 | 12965736092988 |
| 18 | 128543259338048 |
[1,3,7,30,124,733,4586,33373,259434,2152298, 18615182,166544071,1528659536,14328433429, 136649176084,1322594487342,12965736092988, 128543259338048] |