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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 58 |
| 5 | 612 |
| 6 | 8374 |
| 7 | 140408 |
| 8 | 2785906 |
| 9 | 63830764 |
| 10 | 1658336270 |
| 11 | 48169385024 |
| 12 | 1546832023114 |
| 13 | 54413083601268 |
| 14 | 2080827594898342 |
| 15 | 85948745163598088 |
| 16 | 3813417859420469410 |
| 17 | 180876816831806597500 |
| 18 | 9133309115320844870078 |
| 19 | 489156459621633161274704 |
| 20 | 27696066472039561313329018 |
[1,2,8,58,612,8374,140408,2785906,63830764, 1658336270,48169385024,1546832023114, 54413083601268,2080827594898342,85948745163598088, 3813417859420469410,180876816831806597500, 9133309115320844870078,489156459621633161274704, 27696066472039561313329018] |