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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 99 |
| 3 | 261 |
| 4 | 2551 |
| 5 | 14482 |
| 6 | 90381 |
| 7 | 708805 |
| 8 | 4703257 |
| 9 | 33115108 |
| 10 | 242951715 |
| 11 | 1717346931 |
| 12 | 12261739261 |
| 13 | 88279587687 |
| 14 | 632361868337 |
| 15 | 4531624593058 |
| 16 | 32509115649588 |
| 17 | 233191927798253 |
| 18 | 1672553903049280 |
| 19 | 11995741170036801 |
| 20 | 86046219903357310 |
[8,99,261,2551,14482,90381,708805,4703257, 33115108,242951715,1717346931,12261739261, 88279587687,632361868337,4531624593058, 32509115649588,233191927798253,1672553903049280, 11995741170036801,86046219903357310] |