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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 31 |
| 4 | 469 |
| 5 | 9681 |
| 6 | 254701 |
| 7 | 8131999 |
| 8 | 305626329 |
| 9 | 13218345793 |
| 10 | 646712664121 |
| 11 | 35315446759671 |
| 12 | 2129341219106773 |
| 13 | 140506900034640049 |
| 14 | 10071589943109973461 |
| 15 | 779311468200041101711 |
| 16 | 64742128053980794659121 |
| 17 | 5747587082198264156035329 |
| 18 | 543023929087191507383612785 |
[1,1,3,31,469,9681,254701,8131999,305626329, 13218345793,646712664121,35315446759671, 2129341219106773,140506900034640049, 10071589943109973461,779311468200041101711, 64742128053980794659121,5747587082198264156035329, 543023929087191507383612785] |