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| n | a(n) |
|---|---|
| 1 | -1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 131 |
| 5 | 1843 |
| 6 | 97261 |
| 7 | 4683059 |
| 8 | 1331727679 |
| 9 | 568285777 |
| 10 | 9521655609199 |
| 11 | 175554688130609 |
| 12 | 11334988388673161 |
| 13 | 3457026400678609391 |
| 14 | 6594042537777612027841 |
| 15 | 249248595232521829462213 |
| 16 | 268938575250382935485761673113 |
| 17 | 3929672369519648081411955883 |
| 18 | 4719016202742955262333630268611 |
[-1,1,7,131,1843,97261,4683059,1331727679, 568285777,9521655609199,175554688130609, 11334988388673161,3457026400678609391, 6594042537777612027841,249248595232521829462213, 268938575250382935485761673113, 3929672369519648081411955883, 4719016202742955262333630268611] |