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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 30 |
| 4 | 1680 |
| 5 | 201600 |
| 6 | 87091200 |
| 7 | 1103619686400 |
| 8 | 275463473725440000 |
| 9 | 240529195987579699200000 |
| 10 | 1163776461866305616609280000000 |
| 11 | 344605941225348705438623229542400000000 |
| 12 | 3717059729911125118574880410324812431360000000000 |
[1,3,30,1680,201600,87091200,1103619686400, 275463473725440000,240529195987579699200000, 1163776461866305616609280000000, 344605941225348705438623229542400000000, 3717059729911125118574880410324812431360000000000] |