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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 115 |
| 5 | 1281 |
| 6 | 16768 |
| 7 | 286337 |
| 8 | 5457171 |
| 9 | 125801270 |
| 10 | 3653694001 |
| 11 | 113390315301 |
| 12 | 4199095360138 |
| 13 | 172276300080959 |
| 14 | 7412079998841375 |
| 15 | 348540036245625584 |
| 16 | 18480034001016997327 |
| 17 | 1090670546096248467877 |
| 18 | 66549383345872173537824 |
| 19 | 4459899354719531875502085 |
[1,3,16,115,1281,16768,286337,5457171,125801270, 3653694001,113390315301,4199095360138, 172276300080959,7412079998841375, 348540036245625584,18480034001016997327, 1090670546096248467877,66549383345872173537824, 4459899354719531875502085] |