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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 109 |
| 5 | 1061 |
| 6 | 13081 |
| 7 | 196135 |
| 8 | 3470097 |
| 9 | 70807497 |
| 10 | 1637267473 |
| 11 | 42310099331 |
| 12 | 1208419463329 |
| 13 | 37799118682429 |
| 14 | 1285103316125721 |
| 15 | 47184372451150719 |
| 16 | 1860687091374107761 |
| 17 | 78432185337652592657 |
| 18 | 3519258710478790607137 |
| 19 | 167474007086529472461307 |
[1,3,15,109,1061,13081,196135,3470097,70807497, 1637267473,42310099331,1208419463329, 37799118682429,1285103316125721,47184372451150719, 1860687091374107761,78432185337652592657, 3519258710478790607137,167474007086529472461307] |