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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 109 |
| 5 | 449 |
| 6 | 1995 |
| 7 | 8648 |
| 8 | 39542 |
| 9 | 177391 |
| 10 | 824142 |
| 11 | 3780180 |
| 12 | 17757683 |
| 13 | 82638051 |
| 14 | 391512994 |
| 15 | 1840788102 |
| 16 | 8778125385 |
| 17 | 41599169813 |
| 18 | 199370832862 |
| 19 | 950717604657 |
| 20 | 4574750880399 |
| 21 | 21924045003490 |
| 22 | 105846504118961 |
| 23 | 509316666679058 |
| 24 | 2465797422256411 |
| 25 | 11904956817171765 |
| 26 | 57773578111490989 |
| 27 | 279724927288607769 |
[1,2,7,26,109,449,1995,8648,39542,177391,824142, 3780180,17757683,82638051,391512994,1840788102, 8778125385,41599169813,199370832862,950717604657, 4574750880399,21924045003490,105846504118961, 509316666679058,2465797422256411, 11904956817171765,57773578111490989, 279724927288607769] |