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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 18 |
| 4 | 288 |
| 5 | 180000 |
| 6 | 1620000 |
| 7 | 190591380000 |
| 8 | 780662292480000 |
| 9 | 46097327708651520000 |
| 10 | 28810829817907200000000 |
| 11 | 747278726094210559615027200000000 |
| 12 | 747278726094210559615027200000000 |
[1,2,18,288,180000,1620000,190591380000, 780662292480000,46097327708651520000, 28810829817907200000000, 747278726094210559615027200000000, 747278726094210559615027200000000] |