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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 14 |
| 4 | 196 |
| 5 | 4652 |
| 6 | 166168 |
| 7 | 8232296 |
| 8 | 535974416 |
| 9 | 44186331248 |
| 10 | 4489336764064 |
| 11 | 550549455440096 |
| 12 | 80153857492836928 |
| 13 | 13665883723351362752 |
| 14 | 2697370187692768024448 |
| 15 | 610301579538939633684608 |
| 16 | 156933087218604923576672512 |
| 17 | 45515622704384079509089136384 |
| 18 | 14789652457653705738777659937280 |
[1,1,2,14,196,4652,166168,8232296,535974416, 44186331248,4489336764064,550549455440096, 80153857492836928,13665883723351362752, 2697370187692768024448,610301579538939633684608, 156933087218604923576672512, 45515622704384079509089136384, 14789652457653705738777659937280] |