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| n | a(n) |
|---|---|
| 2 | 9 |
| 3 | 252 |
| 4 | 16380 |
| 5 | 2063880 |
| 6 | 447861960 |
| 7 | 154064514240 |
| 8 | 79035095805120 |
| 9 | 57695619937737600 |
| 10 | 57753315557675337600 |
| 11 | 76927416322823549683200 |
| 12 | 133007502822161917402252800 |
| 13 | 292350491203111894450151654400 |
[9,252,16380,2063880,447861960,154064514240, 79035095805120,57695619937737600, 57753315557675337600,76927416322823549683200, 133007502822161917402252800, 292350491203111894450151654400] |