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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 120 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 181440 |
| 10 | 21772800 |
| 11 | 0 |
| 12 | 0 |
| 13 | 2075673600 |
| 14 | 697426329600 |
| 15 | 66691392768000 |
| 16 | 0 |
| 17 | 88921857024000 |
| 18 | 58688425635840000 |
| 19 | 14050009097220096000 |
| 20 | 1231048416137379840000 |
| 21 | 10218188434341888000 |
| 22 | 11240007277776076800000 |
| 23 | 4901111506746943488000000 |
[1,0,0,0,0,120,0,0,0,181440,21772800,0,0, 2075673600,697426329600,66691392768000,0, 88921857024000,58688425635840000, 14050009097220096000,1231048416137379840000, 10218188434341888000,11240007277776076800000, 4901111506746943488000000] |