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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 16 |
| 4 | 74 |
| 5 | 1471 |
| 6 | 48706 |
| 7 | 2390688 |
| 8 | 296920649 |
| 9 | 60945292478 |
| 10 | 24369107078211 |
[1,1,16,74,1471,48706,2390688,296920649, 60945292478,24369107078211] |