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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 7 |
| 4 | 8 |
| 5 | 17 |
| 6 | 214 |
| 7 | 1761 |
| 8 | 8632 |
| 9 | 38969 |
| 10 | 381754 |
| 11 | 5371821 |
| 12 | 56522540 |
| 13 | 533244077 |
| 14 | 6087452310 |
| 15 | 95701880241 |
| 16 | 1458087413200 |
| 17 | 21713687902033 |
| 18 | 333863833250482 |
| 19 | 6101409790911765 |
| 20 | 114840891055289940 |
| 21 | 2263678163011472213 |
[1,2,4,7,8,17,214,1761,8632,38969,381754,5371821, 56522540,533244077,6087452310,95701880241, 1458087413200,21713687902033,333863833250482, 6101409790911765,114840891055289940, 2263678163011472213] |