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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 71 |
| 5 | 469 |
| 6 | 3723 |
| 7 | 36005 |
| 8 | 436547 |
| 9 | 6899269 |
| 10 | 148118063 |
| 11 | 4468393661 |
| 12 | 193343082863 |
| 13 | 12098043923845 |
| 14 | 1095808155971903 |
| 15 | 143385496616202557 |
| 16 | 27027137980334917335 |
| 17 | 7318231233568088061141 |
| 18 | 2839533242388092176367563 |
[1,1,3,13,71,469,3723,36005,436547,6899269, 148118063,4468393661,193343082863,12098043923845, 1095808155971903,143385496616202557, 27027137980334917335,7318231233568088061141, 2839533242388092176367563] |