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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 69 |
| 4 | 629 |
| 5 | 3617 |
| 6 | 23293 |
| 7 | 150639 |
| 8 | 974609 |
| 9 | 6275983 |
| 10 | 40514073 |
| 11 | 261520865 |
| 12 | 1687765963 |
| 13 | 10892349861 |
| 14 | 70298890683 |
| 15 | 453700338187 |
| 16 | 2928104677297 |
| 17 | 18897520747299 |
| 18 | 121961661224043 |
| 19 | 787121398787181 |
| 20 | 5079958229149695 |
[1,9,69,629,3617,23293,150639,974609,6275983, 40514073,261520865,1687765963,10892349861, 70298890683,453700338187,2928104677297, 18897520747299,121961661224043,787121398787181, 5079958229149695] |