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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 69 |
| 4 | 1292 |
| 5 | 35795 |
| 6 | 1381662 |
| 7 | 71137787 |
| 8 | 4723263400 |
| 9 | 393582311685 |
| 10 | 40255365257750 |
| 11 | 4961198428428121 |
| 12 | 725404352867194164 |
| 13 | 124184747391389562735 |
| 14 | 24610467350470767598014 |
| 15 | 5590555396845759790005015 |
| 16 | 1443198598348337621150240912 |
| 17 | 420171257194869987686583296425 |
| 18 | 137030366263275866352884688085734 |
| 19 | 49758716350139864002666237593244717 |
| 20 | 20008715354387819486054019707449804060 |
[1,1,6,69,1292,35795,1381662,71137787,4723263400, 393582311685,40255365257750,4961198428428121, 725404352867194164,124184747391389562735, 24610467350470767598014,5590555396845759790005015, 1443198598348337621150240912, 420171257194869987686583296425, 137030366263275866352884688085734, 49758716350139864002666237593244717, 20008715354387819486054019707449804060] |