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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 8 |
| 2 | 68 |
| 3 | 656 |
| 4 | 6924 |
| 5 | 77816 |
| 6 | 912504 |
| 7 | 11043616 |
| 8 | 136909712 |
| 9 | 1729812880 |
| 10 | 22193496988 |
| 11 | 288368706416 |
| 12 | 3786876943856 |
| 13 | 50180784019384 |
| 14 | 670150485880336 |
| 15 | 9010466250798080 |
| 16 | 121871951481594296 |
| 17 | 1657086342551799752 |
| 18 | 22637216782139196588 |
| 19 | 310547100988853539728 |
[3,8,68,656,6924,77816,912504,11043616,136909712, 1729812880,22193496988,288368706416,3786876943856, 50180784019384,670150485880336,9010466250798080, 121871951481594296,1657086342551799752, 22637216782139196588,310547100988853539728] |