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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 21 |
| 2 | 285 |
| 3 | 3333 |
| 4 | 44589 |
| 5 | 609441 |
| 6 | 8484027 |
| 7 | 119207781 |
| 8 | 1683956109 |
| 9 | 23857954869 |
| 10 | 338563579455 |
| 11 | 4808766812871 |
| 12 | 68334330572247 |
| 13 | 971314874179749 |
| 14 | 13808436456553037 |
| 15 | 196319581589707923 |
| 16 | 2791268881281069805 |
[1,21,285,3333,44589,609441,8484027,119207781, 1683956109,23857954869,338563579455,4808766812871, 68334330572247,971314874179749,13808436456553037, 196319581589707923,2791268881281069805] |