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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 12 |
| 5 | 60 |
| 6 | 360 |
| 7 | 2520 |
| 8 | 5040 |
| 9 | 15120 |
| 10 | 151200 |
| 11 | 1663200 |
| 12 | 19958400 |
| 13 | 259459200 |
| 14 | 3632428800 |
| 15 | 54486432000 |
| 16 | 108972864000 |
| 17 | 1852538688000 |
| 18 | 33345696384000 |
| 19 | 633568231296000 |
| 20 | 12671364625920000 |
| 21 | 266098657144320000 |
| 22 | 5854170457175040000 |
| 23 | 134645920515025920000 |
[1,1,2,6,12,60,360,2520,5040,15120,151200,1663200, 19958400,259459200,3632428800,54486432000, 108972864000,1852538688000,33345696384000, 633568231296000,12671364625920000, 266098657144320000,5854170457175040000, 134645920515025920000] |