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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 37 |
| 5 | 189 |
| 6 | 1138 |
| 7 | 7970 |
| 8 | 63763 |
| 9 | 573871 |
| 10 | 5738715 |
| 11 | 63125866 |
| 12 | 757510403 |
| 13 | 9847635243 |
| 14 | 137866893402 |
| 15 | 2068003401034 |
| 16 | 33088054416552 |
| 17 | 562496925081397 |
| 18 | 10124944651465158 |
| 19 | 192373948377838002 |
| 20 | 3847478967556760044 |
[1,3,9,37,189,1138,7970,63763,573871,5738715, 63125866,757510403,9847635243,137866893402, 2068003401034,33088054416552,562496925081397, 10124944651465158,192373948377838002, 3847478967556760044] |