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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 77 |
| 4 | 799 |
| 5 | 8625 |
| 6 | 95381 |
| 7 | 1072072 |
| 8 | 12191464 |
| 9 | 139863218 |
| 10 | 1615571749 |
| 11 | 18764341805 |
| 12 | 218924287555 |
| 13 | 2563800729881 |
| 14 | 30119987939735 |
| 15 | 354820919500737 |
| 16 | 4189771263878559 |
| 17 | 49575855774030751 |
| 18 | 587683571695829594 |
| 19 | 6977862787102136461 |
| 20 | 82972236113530966223 |
| 21 | 987897037991665663841 |
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