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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 28 |
| 6 | 572 |
| 7 | 87210 |
| 8 | 379629720 |
| 9 | 336691526641470 |
| 10 | 1730145467127958158326862 |
| 11 | 10298346936926006723717705424338819472320 |
| 12 | 408365746142143027393604600897014805299276160859821396471640832240 |
| 13 | 124021818977464152348319837503281224966237629433185201999567260096859939574786766596034209404972486842291250 |
[1,1,2,5,28,572,87210,379629720,336691526641470, 1730145467127958158326862, 10298346936926006723717705424338819472320, 40836574614214302739360460089701480529927616085982\ 1396471640832240, 12402181897746415234831983750328122496623762943318\ 52019995672600968599395747867665960342094049724868\ 42291250] |