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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 26 |
| 4 | 367 |
| 5 | 7142 |
| 6 | 176766 |
| 7 | 5304356 |
| 8 | 186954535 |
| 9 | 7566084686 |
| 10 | 345664350778 |
| 11 | 17592776858796 |
| 12 | 986961816330662 |
| 13 | 60502424162842876 |
| 14 | 4023421969420255644 |
| 15 | 288464963899330354104 |
| 16 | 22180309834307193611287 |
| 17 | 1820641848410408158704734 |
| 18 | 158897008602951290424279330 |
[1,3,26,367,7142,176766,5304356,186954535, 7566084686,345664350778,17592776858796, 986961816330662,60502424162842876, 4023421969420255644,288464963899330354104, 22180309834307193611287,1820641848410408158704734, 158897008602951290424279330] |