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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 56 |
| 3 | 16064 |
| 4 | 39156608 |
| 5 | 813732073472 |
| 6 | 147662286695991296 |
| 7 | 237776857718965784182784 |
| 8 | 3425329990022686416530808209408 |
| 9 | 443021337239562368918979788606843912192 |
| 10 | 515203019085226443540506018909263027730003787776 |
[1,2,56,16064,39156608,813732073472, 147662286695991296,237776857718965784182784, 3425329990022686416530808209408, 443021337239562368918979788606843912192, 515203019085226443540506018909263027730003787776] |