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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 24 |
| 6 | 50 |
| 7 | 720 |
| 8 | 4095 |
| 9 | 35840 |
| 10 | 267624 |
| 11 | 3628800 |
| 12 | 35724150 |
| 13 | 479001600 |
| 14 | 5240149200 |
| 15 | 82614884352 |
| 16 | 1188272460375 |
| 17 | 20922789888000 |
| 18 | 320893244672000 |
| 19 | 6402373705728000 |
| 20 | 113803149223980216 |
| 21 | 2379913632645120000 |
| 22 | 46396417566975840000 |
| 23 | 1124000727777607680000 |
[0,1,2,3,24,50,720,4095,35840,267624,3628800, 35724150,479001600,5240149200,82614884352, 1188272460375,20922789888000,320893244672000, 6402373705728000,113803149223980216, 2379913632645120000,46396417566975840000, 1124000727777607680000] |