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| n | a(n) |
|---|---|
| 1 | 5 |
| 2 | 26 |
| 3 | 121 |
| 4 | 547 |
| 5 | 2644 |
| 6 | 13504 |
| 7 | 69858 |
| 8 | 361448 |
| 9 | 1827707 |
| 10 | 8901990 |
| 11 | 42510428 |
| 12 | 205423322 |
| 13 | 1020648167 |
| 14 | 5181556417 |
| 15 | 26415622622 |
| 16 | 133002076952 |
| 17 | 656895200707 |
| 18 | 3202519957155 |
| 19 | 15628783471819 |
| 20 | 77223050176456 |
| 21 | 386855148392695 |
[5,26,121,547,2644,13504,69858,361448,1827707, 8901990,42510428,205423322,1020648167,5181556417, 26415622622,133002076952,656895200707, 3202519957155,15628783471819,77223050176456, 386855148392695] |