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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 6 |
| 4 | 12 |
| 5 | 120 |
| 6 | 360 |
| 7 | 5040 |
| 8 | 20160 |
| 9 | 362880 |
| 10 | 1814400 |
| 11 | 39916800 |
| 12 | 239500800 |
| 13 | 6227020800 |
| 14 | 43589145600 |
| 15 | 1307674368000 |
| 16 | 10461394944000 |
| 17 | 355687428096000 |
| 18 | 3201186852864000 |
| 19 | 121645100408832000 |
| 20 | 1216451004088320000 |
| 21 | 51090942171709440000 |
| 22 | 562000363888803840000 |
[1,1,6,12,120,360,5040,20160,362880,1814400, 39916800,239500800,6227020800,43589145600, 1307674368000,10461394944000,355687428096000, 3201186852864000,121645100408832000, 1216451004088320000,51090942171709440000, 562000363888803840000] |