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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 7 |
| 3 | 241 |
| 4 | 15121 |
| 5 | 4324321 |
| 6 | 39070081 |
| 7 | 29837808001 |
| 8 | 17081356723201 |
| 9 | 1607854392144001 |
| 10 | 106137499051584001 |
| 11 | 42873948150095462401 |
| 12 | 83214009097971687936001 |
| 13 | 23877922252236982465536001 |
[2,7,241,15121,4324321,39070081,29837808001, 17081356723201,1607854392144001, 106137499051584001,42873948150095462401, 83214009097971687936001, 23877922252236982465536001] |