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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 720 |
| 9 | 5760 |
| 10 | 12240 |
| 11 | 42480 |
| 12 | 182160 |
| 13 | 953280 |
| 14 | 5901840 |
| 15 | 42266160 |
| 16 | 11803680 |
| 17 | 96336000 |
| 18 | 216279360 |
| 19 | 841510080 |
| 20 | 3798599040 |
| 21 | 20676015360 |
| 22 | 131653290240 |
| 23 | 962925062400 |
| 24 | 394959870720 |
| 25 | 3283735057920 |
| 26 | 7752349728000 |
[1,1,2,6,24,120,720,5040,720,5760,12240,42480, 182160,953280,5901840,42266160,11803680,96336000, 216279360,841510080,3798599040,20676015360, 131653290240,962925062400,394959870720, 3283735057920,7752349728000] |