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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 6 |
| 4 | 0 |
| 5 | 0 |
| 6 | 360 |
| 7 | 0 |
| 8 | 0 |
| 9 | 60480 |
| 10 | 0 |
| 11 | 0 |
| 12 | 19958400 |
| 13 | 0 |
| 14 | 0 |
| 15 | 10897286400 |
| 16 | 0 |
| 17 | 0 |
| 18 | 8892185702400 |
| 19 | 0 |
| 20 | 0 |
| 21 | 10137091700736000 |
| 22 | 0 |
| 23 | 0 |
| 24 | 15388105201717248000 |
| 25 | 0 |
| 26 | 0 |
| 27 | 30006805143348633600000 |
| 28 | 0 |
| 29 | 0 |
| 30 | 73096577329197271449600000 |
[1,0,0,6,0,0,360,0,0,60480,0,0,19958400,0,0, 10897286400,0,0,8892185702400,0,0, 10137091700736000,0,0,15388105201717248000,0,0, 30006805143348633600000,0,0, 73096577329197271449600000] |