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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 12 |
| 4 | 264 |
| 5 | 7858 |
| 6 | 282972 |
| 7 | 11675841 |
| 8 | 535230939 |
| 9 | 26735073957 |
| 10 | 1436236487580 |
| 11 | 82211207568861 |
| 12 | 4979654512195446 |
| 13 | 317494071032079069 |
| 14 | 21219516654529825396 |
| 15 | 1481652170309786445597 |
| 16 | 107788957126134284934186 |
| 17 | 8151161821017797142225705 |
| 18 | 639483016955485718843031996 |
[1,1,12,264,7858,282972,11675841,535230939, 26735073957,1436236487580,82211207568861, 4979654512195446,317494071032079069, 21219516654529825396,1481652170309786445597, 107788957126134284934186, 8151161821017797142225705, 639483016955485718843031996] |