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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1120 |
| 3 | 110880 |
| 4 | 1441440 |
| 5 | 5189184 |
| 6 | 58605120 |
| 7 | 349949600 |
| 8 | 639381600 |
| 9 | 3765731200 |
| 10 | 12841684128 |
| 11 | 136367431200 |
| 12 | 1442885004000 |
| 13 | 4895245266912 |
| 14 | 28461435424576 |
| 15 | 51671930508000 |
| 16 | 300266024938880 |
| 17 | 3166522452945280 |
| 18 | 10732052830603104 |
[0,1120,110880,1441440,5189184,58605120,349949600, 639381600,3765731200,12841684128,136367431200, 1442885004000,4895245266912,28461435424576, 51671930508000,300266024938880,3166522452945280, 10732052830603104] |