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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 124 |
| 5 | 1820 |
| 6 | 34476 |
| 7 | 796600 |
| 8 | 21647088 |
| 9 | 674894736 |
| 10 | 23727325600 |
| 11 | 929120132336 |
| 12 | 40145865303072 |
| 13 | 1899037891380448 |
| 14 | 97624128373666272 |
| 15 | 5416162739385169920 |
| 16 | 322369745413410839296 |
| 17 | 20496143199154076929280 |
[1,2,12,124,1820,34476,796600,21647088,674894736, 23727325600,929120132336,40145865303072, 1899037891380448,97624128373666272, 5416162739385169920,322369745413410839296, 20496143199154076929280] |