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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 18 |
| 3 | 146 |
| 4 | 1332 |
| 5 | 13089 |
| 6 | 135307 |
| 7 | 1451118 |
| 8 | 15999321 |
| 9 | 180244790 |
| 10 | 2065946265 |
[3,18,146,1332,13089,135307,1451118,15999321, 180244790,2065946265] |