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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 51 |
| 4 | 513 |
| 5 | 6345 |
| 6 | 93255 |
| 7 | 1584555 |
| 8 | 30524865 |
| 9 | 656843985 |
| 10 | 15605162055 |
| 11 | 405495737955 |
| 12 | 11435339115585 |
| 13 | 347722239169305 |
| 14 | 11337916544369415 |
| 15 | 394530748734397275 |
| 16 | 14590576590956791425 |
| 17 | 571378543704076133025 |
| 18 | 23617402334089770781575 |
[1,7,51,513,6345,93255,1584555,30524865,656843985, 15605162055,405495737955,11435339115585, 347722239169305,11337916544369415, 394530748734397275,14590576590956791425, 571378543704076133025,23617402334089770781575] |