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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 23 |
| 3 | 195 |
| 4 | 2229 |
| 5 | 31863 |
| 6 | 546255 |
| 7 | 10925757 |
| 8 | 249753897 |
| 9 | 6422808411 |
| 10 | 183524701779 |
| 11 | 5768419379913 |
| 12 | 197791542799965 |
| 13 | 7347180526444359 |
| 14 | 293912722687075767 |
| 15 | 12597352573293062757 |
| 16 | 575928946256877156177 |
| 17 | 27976119070974574461363 |
| 18 | 1438896686251112024068251 |
[1,4,23,195,2229,31863,546255,10925757,249753897, 6422808411,183524701779,5768419379913, 197791542799965,7347180526444359, 293912722687075767,12597352573293062757, 575928946256877156177,27976119070974574461363, 1438896686251112024068251] |