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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 11 |
| 3 | 89 |
| 4 | 715 |
| 5 | 5721 |
| 6 | 45771 |
| 7 | 366169 |
| 8 | 2929355 |
| 9 | 23434841 |
| 10 | 187478731 |
| 11 | 1499829849 |
| 12 | 11998638795 |
| 13 | 95989110361 |
| 14 | 767912882891 |
| 15 | 6143303063129 |
| 16 | 49146424505035 |
| 17 | 393171396040281 |
| 18 | 3145371168322251 |
| 19 | 25162969346578009 |
| 20 | 201303754772624075 |
| 21 | 1610430038180992601 |
[1,11,89,715,5721,45771,366169,2929355,23434841, 187478731,1499829849,11998638795,95989110361, 767912882891,6143303063129,49146424505035, 393171396040281,3145371168322251, 25162969346578009,201303754772624075, 1610430038180992601] |