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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 56 |
| 4 | 957 |
| 5 | 22312 |
| 6 | 666666 |
| 7 | 24367474 |
| 8 | 1051351629 |
| 9 | 52144520972 |
| 10 | 2915915251326 |
| 11 | 181227240764128 |
| 12 | 12382862552065170 |
| 13 | 922234506009645794 |
| 14 | 74345308066436693828 |
| 15 | 6449466281781165675666 |
| 16 | 599083515375854753327365 |
| 17 | 59328642583049975996828036 |
| 18 | 6240245388930730524658068558 |
| 19 | 694754212357547941002786433000 |
| 20 | 81628078642468462576697539116234 |
[1,1,5,56,957,22312,666666,24367474,1051351629, 52144520972,2915915251326,181227240764128, 12382862552065170,922234506009645794, 74345308066436693828,6449466281781165675666, 599083515375854753327365, 59328642583049975996828036, 6240245388930730524658068558, 694754212357547941002786433000, 81628078642468462576697539116234] |