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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 120 |
| 6 | 720 |
| 7 | 40320 |
| 8 | 362880 |
| 9 | 39916800 |
| 10 | 87178291200 |
| 11 | 1307674368000 |
| 12 | 6402373705728000 |
| 13 | 2432902008176640000 |
| 14 | 51090942171709440000 |
| 15 | 25852016738884976640000 |
| 16 | 403291461126605635584000000 |
| 17 | 8841761993739701954543616000000 |
[1,2,6,120,720,40320,362880,39916800,87178291200, 1307674368000,6402373705728000, 2432902008176640000,51090942171709440000, 25852016738884976640000, 403291461126605635584000000, 8841761993739701954543616000000] |