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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 89 |
| 5 | 327 |
| 6 | 1353 |
| 7 | 6303 |
| 8 | 32953 |
| 9 | 192395 |
| 10 | 1247473 |
| 11 | 8931643 |
| 12 | 70221841 |
| 13 | 603040399 |
| 14 | 5628477521 |
| 15 | 56832554399 |
| 16 | 618172840753 |
| 17 | 7214736795987 |
| 18 | 90023735419577 |
| 19 | 1196943617218715 |
| 20 | 16905957430843689 |
| 21 | 252946811300548119 |
[1,3,9,27,89,327,1353,6303,32953,192395,1247473, 8931643,70221841,603040399,5628477521,56832554399, 618172840753,7214736795987,90023735419577, 1196943617218715,16905957430843689, 252946811300548119] |