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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 40320 |
| 9 | 362880 |
| 10 | 1814400 |
| 11 | 8316000 |
| 12 | 37920960 |
| 13 | 176833800 |
| 14 | 852972120 |
| 15 | 4277399490 |
| 16 | 22346336880 |
| 17 | 121693555905 |
| 18 | 690665206113 |
| 19 | 3742590924108 |
| 20 | 19625337285660 |
| 21 | 101084160732660 |
| 22 | 516806625700056 |
| 23 | 2640952527095376 |
| 24 | 13549247936670720 |
[1,1,2,6,24,120,720,5040,40320,362880,1814400, 8316000,37920960,176833800,852972120,4277399490, 22346336880,121693555905,690665206113, 3742590924108,19625337285660,101084160732660, 516806625700056,2640952527095376, 13549247936670720] |