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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 12 |
| 3 | 228 |
| 4 | 5928 |
| 5 | 195624 |
| 6 | 7824960 |
| 7 | 367773120 |
| 8 | 19859748480 |
| 9 | 1211444657280 |
| 10 | 82378236695040 |
| 11 | 6178367752128000 |
| 12 | 506626155674496000 |
| 13 | 45089727855030144000 |
| 14 | 4328613874082893824000 |
| 15 | 445847229030538063872000 |
| 16 | 49043195193359187025920000 |
| 17 | 5738053837623024882032640000 |
[1,12,228,5928,195624,7824960,367773120, 19859748480,1211444657280,82378236695040, 6178367752128000,506626155674496000, 45089727855030144000,4328613874082893824000, 445847229030538063872000, 49043195193359187025920000, 5738053837623024882032640000] |