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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 28 |
| 3 | 98 |
| 4 | 396 |
| 5 | 2075 |
| 6 | 9140 |
| 7 | 40412 |
| 8 | 189729 |
| 9 | 873060 |
| 10 | 3979064 |
| 11 | 18356703 |
| 12 | 84632174 |
| 13 | 389029015 |
| 14 | 1791954662 |
| 15 | 8257849953 |
| 16 | 38030907288 |
| 17 | 175204408009 |
| 18 | 807291828371 |
| 19 | 3719389877395 |
| 20 | 17136993336823 |
| 21 | 78962057731073 |
| 22 | 363828807655049 |
[8,28,98,396,2075,9140,40412,189729,873060, 3979064,18356703,84632174,389029015,1791954662, 8257849953,38030907288,175204408009,807291828371, 3719389877395,17136993336823,78962057731073, 363828807655049] |