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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 168 |
| 2 | 85680 |
| 3 | 50388000 |
| 4 | 31479903000 |
| 5 | 20342022734880 |
| 6 | 13431668094985140 |
| 7 | 9002968680250888200 |
| 8 | 6101557410115488321000 |
| 9 | 4170391891453158061891200 |
| 10 | 2869634745103513910507157888 |
| 11 | 1985363415926004500849300108544 |
| 12 | 1379778913200535726019164327886400 |
| 13 | 962553011288199733460143650698784000 |
[1,168,85680,50388000,31479903000,20342022734880, 13431668094985140,9002968680250888200, 6101557410115488321000,4170391891453158061891200, 2869634745103513910507157888, 1985363415926004500849300108544, 1379778913200535726019164327886400, 962553011288199733460143650698784000] |