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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 49 |
| 4 | 489 |
| 5 | 6521 |
| 6 | 108643 |
| 7 | 2178107 |
| 8 | 51084337 |
| 9 | 1373054833 |
| 10 | 41624314371 |
| 11 | 1405311853595 |
| 12 | 52299954524953 |
| 13 | 2127347522554073 |
| 14 | 93902399411048803 |
| 15 | 4470613587492385051 |
| 16 | 228362858274694209249 |
| 17 | 12458393118650371672673 |
| 18 | 722983769486947261178371 |
[1,2,7,49,489,6521,108643,2178107,51084337, 1373054833,41624314371,1405311853595, 52299954524953,2127347522554073,93902399411048803, 4470613587492385051,228362858274694209249, 12458393118650371672673,722983769486947261178371] |