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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 19 |
| 4 | 109 |
| 5 | 921 |
| 6 | 8911 |
| 7 | 100003 |
| 8 | 1307769 |
| 9 | 18748369 |
| 10 | 307713691 |
| 11 | 5379610611 |
| 12 | 106277271013 |
| 13 | 2194176659689 |
| 14 | 50689643777319 |
| 15 | 1207518763542211 |
| 16 | 31940171681228401 |
| 17 | 862606920178886433 |
| 18 | 25708097594461923379 |
| 19 | 776354747057987797459 |
| 20 | 25741373454075987900381 |
[1,1,3,19,109,921,8911,100003,1307769,18748369, 307713691,5379610611,106277271013,2194176659689, 50689643777319,1207518763542211,31940171681228401, 862606920178886433,25708097594461923379, 776354747057987797459,25741373454075987900381] |