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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 143 |
| 3 | 1126 |
| 4 | 9904 |
| 5 | 88509 |
| 6 | 834717 |
| 7 | 7843113 |
| 8 | 73725405 |
| 9 | 697624797 |
| 10 | 6644826507 |
| 11 | 63556636483 |
| 12 | 609902716100 |
| 13 | 5871497904831 |
| 14 | 56683948490522 |
| 15 | 548487091412193 |
| 16 | 5317814454716839 |
| 17 | 51651465543152430 |
| 18 | 502495332741155890 |
[20,143,1126,9904,88509,834717,7843113,73725405, 697624797,6644826507,63556636483,609902716100, 5871497904831,56683948490522,548487091412193, 5317814454716839,51651465543152430, 502495332741155890] |