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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 34 |
| 4 | 173 |
| 5 | 1066 |
| 6 | 7147 |
| 7 | 51962 |
| 8 | 412729 |
| 9 | 3478258 |
| 10 | 31220111 |
| 11 | 296409202 |
| 12 | 2953487077 |
| 13 | 30870965594 |
| 14 | 336796018483 |
| 15 | 3824230997386 |
| 16 | 45114077004017 |
| 17 | 551338045973602 |
| 18 | 6968344940992279 |
| 19 | 90931562913957698 |
| 20 | 1222939213021853341 |
| 21 | 16929504703420184842 |
| 22 | 240909000856701880187 |
[1,2,7,34,173,1066,7147,51962,412729,3478258, 31220111,296409202,2953487077,30870965594, 336796018483,3824230997386,45114077004017, 551338045973602,6968344940992279, 90931562913957698,1222939213021853341, 16929504703420184842,240909000856701880187] |