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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 48 |
| 3 | 480 |
| 4 | 4032 |
| 5 | 31104 |
| 6 | 228096 |
| 7 | 1617408 |
| 8 | 11197440 |
| 9 | 76142592 |
| 10 | 510603264 |
| 11 | 3386105856 |
| 12 | 22251552768 |
| 13 | 145118822400 |
| 14 | 940369969152 |
| 15 | 6060162023424 |
| 16 | 38868625391616 |
| 17 | 248257671856128 |
| 18 | 1579821548175360 |
| 19 | 10020582391283712 |
[0,48,480,4032,31104,228096,1617408,11197440, 76142592,510603264,3386105856,22251552768, 145118822400,940369969152,6060162023424, 38868625391616,248257671856128,1579821548175360, 10020582391283712] |