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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 63 |
| 3 | 496 |
| 4 | 3904 |
| 5 | 30729 |
| 6 | 241871 |
| 7 | 1903792 |
| 8 | 14984945 |
| 9 | 117948062 |
| 10 | 928381475 |
| 11 | 7307387240 |
| 12 | 57517205708 |
| 13 | 452723914009 |
| 14 | 3563437058402 |
| 15 | 28048184061555 |
| 16 | 220770176730345 |
| 17 | 1737705044525640 |
| 18 | 13677657310833723 |
| 19 | 107658264618591797 |
| 20 | 847389408675004032 |
| 21 | 6669890253930098674 |
[1,8,63,496,3904,30729,241871,1903792,14984945, 117948062,928381475,7307387240,57517205708, 452723914009,3563437058402,28048184061555, 220770176730345,1737705044525640, 13677657310833723,107658264618591797, 847389408675004032,6669890253930098674] |