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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 7 |
| 3 | 17 |
| 4 | 45 |
| 5 | 135 |
| 6 | 463 |
| 7 | 1817 |
| 8 | 8121 |
| 9 | 41075 |
| 10 | 233471 |
| 11 | 1480945 |
| 12 | 10412589 |
| 13 | 80634431 |
| 14 | 683674831 |
| 15 | 6312152353 |
| 16 | 63144706753 |
| 17 | 681317547507 |
| 18 | 7896054343495 |
| 19 | 97919789763073 |
| 20 | 1294863406981789 |
| 21 | 18200820837825479 |
| 22 | 271147632138373599 |
[1,3,7,17,45,135,463,1817,8121,41075,233471, 1480945,10412589,80634431,683674831,6312152353, 63144706753,681317547507,7896054343495, 97919789763073,1294863406981789,18200820837825479, 271147632138373599] |