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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 31 |
| 5 | 26129 |
| 6 | 466202136816810031 |
| 7 | 10584868011442581563053546190350068005080430521324963528734180259722815036145 |
[1,2,4,31,26129,466202136816810031, 10584868011442581563053546190350068005080430521324\ 963528734180259722815036145] |