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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 1 |
| 3 | 72 |
| 4 | 12 |
| 5 | 12 |
| 6 | 43200 |
| 7 | 3600 |
| 8 | 1440 |
| 9 | 2160 |
| 10 | 423360000 |
| 11 | 21168000 |
| 12 | 4704000 |
| 13 | 3024000 |
| 14 | 6048000 |
| 15 | 67212633600000 |
| 16 | 2240421120000 |
| 17 | 320060160000 |
| 18 | 120022560000 |
| 19 | 106686720000 |
| 20 | 266716800000 |
| 21 | 172153600393420800000 |
| 22 | 4098895247462400000 |
[1,2,1,72,12,12,43200,3600,1440,2160,423360000, 21168000,4704000,3024000,6048000,67212633600000, 2240421120000,320060160000,120022560000, 106686720000,266716800000,172153600393420800000, 4098895247462400000] |