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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 8 |
| 4 | 18 |
| 5 | 61 |
| 6 | 168 |
| 7 | 526 |
| 8 | 1643 |
| 9 | 5524 |
| 10 | 18762 |
| 11 | 65149 |
| 12 | 228440 |
| 13 | 807770 |
| 14 | 2872483 |
| 15 | 10255424 |
| 16 | 36709394 |
| 17 | 131630309 |
| 18 | 472542776 |
| 19 | 1697728566 |
| 20 | 6102699043 |
| 21 | 21944561100 |
| 22 | 78928279002 |
| 23 | 283926402165 |
| 24 | 1021465508456 |
| 25 | 3675119389202 |
| 26 | 13223276351667 |
[2,3,8,18,61,168,526,1643,5524,18762,65149,228440, 807770,2872483,10255424,36709394,131630309, 472542776,1697728566,6102699043,21944561100, 78928279002,283926402165,1021465508456, 3675119389202,13223276351667] |