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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 81 |
| 3 | 308 |
| 4 | 1047 |
| 5 | 4237 |
| 6 | 18513 |
| 7 | 79945 |
| 8 | 344190 |
| 9 | 1508465 |
| 10 | 6674176 |
| 11 | 29600788 |
| 12 | 131609799 |
| 13 | 587110082 |
| 14 | 2625016947 |
| 15 | 11752855152 |
| 16 | 52678292451 |
| 17 | 236333170151 |
| 18 | 1061002713735 |
| 19 | 4765681686396 |
| 20 | 21414073733214 |
| 21 | 96250281021248 |
[8,81,308,1047,4237,18513,79945,344190,1508465, 6674176,29600788,131609799,587110082,2625016947, 11752855152,52678292451,236333170151, 1061002713735,4765681686396,21414073733214, 96250281021248] |