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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 1020 |
| 6 | 60120 |
| 7 | 4207140 |
| 8 | 32160568320 |
| 9 | 2718954045547227180 |
| 10 | 207010809050400405050407020207010800 |
| 11 | 22077011088099055044004405505504407702202207701108800 |
| 12 | 24240848401212096960108108060600484800484806060060600484808484024240242408484012120969600 |
[1,1,2,6,24,1020,60120,4207140,32160568320, 2718954045547227180, 207010809050400405050407020207010800, 22077011088099055044004405505504407702202207701108\ 800, 24240848401212096960108108060600484800484806060060\ 600484808484024240242408484012120969600] |