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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 81 |
| 3 | 351 |
| 4 | 1521 |
| 5 | 8463 |
| 6 | 47089 |
| 7 | 241087 |
| 8 | 1234321 |
| 9 | 6520459 |
| 10 | 34445161 |
| 11 | 179832029 |
| 12 | 938870881 |
| 13 | 4924284469 |
| 14 | 25827382681 |
| 15 | 135217499129 |
| 16 | 707921987161 |
| 17 | 3708936179293 |
| 18 | 19431812871409 |
| 19 | 101777874172609 |
| 20 | 533081279633809 |
[9,81,351,1521,8463,47089,241087,1234321,6520459, 34445161,179832029,938870881,4924284469, 25827382681,135217499129,707921987161, 3708936179293,19431812871409,101777874172609, 533081279633809] |