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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 9 |
| 3 | 45 |
| 4 | 246 |
| 5 | 1485 |
| 6 | 9432 |
| 7 | 62625 |
| 8 | 428319 |
| 9 | 3000393 |
| 10 | 21410436 |
| 11 | 155106693 |
| 12 | 1137703869 |
| 13 | 8432624850 |
| 14 | 63060142671 |
| 15 | 475196487363 |
| 16 | 3604851603690 |
| 17 | 27507181503069 |
| 18 | 210988219961637 |
| 19 | 1625848092941463 |
| 20 | 12580709718788622 |
| 21 | 97714211996345868 |
| 22 | 761528782558088202 |
[3,9,45,246,1485,9432,62625,428319,3000393, 21410436,155106693,1137703869,8432624850, 63060142671,475196487363,3604851603690, 27507181503069,210988219961637,1625848092941463, 12580709718788622,97714211996345868, 761528782558088202] |