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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 144 |
| 5 | 4320 |
| 6 | 233280 |
| 7 | 29393280 |
| 8 | 7054387200 |
| 9 | 3555411148800 |
| 10 | 3519857037312000 |
| 11 | 7201627498340352000 |
| 12 | 28950542543328215040000 |
| 13 | 237104943429858081177600000 |
| 14 | 3853903750508913251460710400000 |
| 15 | 126138269754156730720309051392000000 |
| 16 | 8234306249551351381421774874869760000000 |
| 17 | 1079270520128695625562952032849179443200000000 |
| 18 | 282311265573183686952254740944556962034483200000000 |
[1,2,12,144,4320,233280,29393280,7054387200, 3555411148800,3519857037312000, 7201627498340352000,28950542543328215040000, 237104943429858081177600000, 3853903750508913251460710400000, 126138269754156730720309051392000000, 8234306249551351381421774874869760000000, 1079270520128695625562952032849179443200000000, 28231126557318368695225474094455696203448320000000\ 0] |