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| n | a(n) |
|---|---|
| 0 | 6 |
| 1 | 41 |
| 2 | 251 |
| 3 | 1511 |
| 4 | 9071 |
| 5 | 54431 |
| 6 | 326591 |
| 7 | 1959551 |
| 8 | 11757311 |
| 9 | 70543871 |
| 10 | 423263231 |
| 11 | 2539579391 |
| 12 | 15237476351 |
| 13 | 91424858111 |
| 14 | 548549148671 |
| 15 | 3291294892031 |
| 16 | 19747769352191 |
| 17 | 118486616113151 |
| 18 | 710919696678911 |
| 19 | 4265518180073471 |
| 20 | 25593109080440831 |
[6,41,251,1511,9071,54431,326591,1959551,11757311, 70543871,423263231,2539579391,15237476351, 91424858111,548549148671,3291294892031, 19747769352191,118486616113151,710919696678911, 4265518180073471,25593109080440831] |