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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 5 |
| 3 | 8 |
| 4 | 17 |
| 5 | 54 |
| 6 | 247 |
| 7 | 1448 |
| 8 | 10089 |
| 9 | 80650 |
| 10 | 725771 |
| 11 | 7257612 |
| 12 | 79833613 |
| 13 | 958003214 |
| 14 | 12454041615 |
| 15 | 174356582416 |
| 16 | 2615348736017 |
| 17 | 41845579776018 |
| 18 | 711374856192019 |
| 19 | 12804747411456020 |
| 20 | 243290200817664021 |
| 21 | 4865804016353280022 |
| 22 | 102181884343418880023 |
| 23 | 2248001455555215360024 |
[4,5,8,17,54,247,1448,10089,80650,725771,7257612, 79833613,958003214,12454041615,174356582416, 2615348736017,41845579776018,711374856192019, 12804747411456020,243290200817664021, 4865804016353280022,102181884343418880023, 2248001455555215360024] |