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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 60 |
| 3 | 140 |
| 4 | 420 |
| 5 | 3780 |
| 6 | 17160 |
| 7 | 28600 |
| 8 | 40040 |
| 9 | 138600 |
| 10 | 120120 |
| 11 | 180180 |
| 12 | 300300 |
| 13 | 360360 |
| 14 | 600600 |
| 15 | 1351350 |
| 16 | 900900 |
| 17 | 4144140 |
| 18 | 1801800 |
| 19 | 3063060 |
| 20 | 5405400 |
| 21 | 6126120 |
| 22 | 8558550 |
| 23 | 7657650 |
| 24 | 19399380 |
| 25 | 20720700 |
| 26 | 17117100 |
| 27 | 15315300 |
| 28 | 29099070 |
| 29 | 30630600 |
| 30 | 45945900 |
| 31 | 70450380 |
| 32 | 91891800 |
| 33 | 87297210 |
[1,6,60,140,420,3780,17160,28600,40040,138600, 120120,180180,300300,360360,600600,1351350,900900, 4144140,1801800,3063060,5405400,6126120,8558550, 7657650,19399380,20720700,17117100,15315300, 29099070,30630600,45945900,70450380,91891800, 87297210] |