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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 64 |
| 3 | 506 |
| 4 | 3916 |
| 5 | 29498 |
| 6 | 215524 |
| 7 | 1527506 |
| 8 | 10528876 |
| 9 | 70841738 |
| 10 | 467044084 |
| 11 | 3027621506 |
| 12 | 19356463036 |
| 13 | 122355512378 |
| 14 | 766290978244 |
| 15 | 4762898595506 |
| 16 | 29420807536396 |
| 17 | 180813134269418 |
| 18 | 1106606890266004 |
| 19 | 6749433735297506 |
| 20 | 41050188511748956 |
| 21 | 249087606867080858 |
[8,64,506,3916,29498,215524,1527506,10528876, 70841738,467044084,3027621506,19356463036, 122355512378,766290978244,4762898595506, 29420807536396,180813134269418,1106606890266004, 6749433735297506,41050188511748956, 249087606867080858] |