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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 10 |
| 4 | 180 |
| 5 | 9120 |
| 6 | 1520742 |
| 7 | 878908844 |
| 8 | 1791588717764 |
| 9 | 13024366540532952 |
| 10 | 341234368845828951004 |
| 11 | 32522226812040344643993088 |
| 12 | 11366680383641301437820379768750 |
| 13 | 14669062959091969068110415719779627436 |
[1,1,10,180,9120,1520742,878908844,1791588717764, 13024366540532952,341234368845828951004, 32522226812040344643993088, 11366680383641301437820379768750, 14669062959091969068110415719779627436] |