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| n | a(n) |
|---|---|
| 1 | 641 |
| 2 | 4219 |
| 3 | 28655 |
| 4 | 187203 |
| 5 | 1226781 |
| 6 | 8090191 |
| 7 | 53254665 |
| 8 | 350253925 |
| 9 | 2304752967 |
| 10 | 15167443677 |
| 11 | 99803396861 |
| 12 | 656712280793 |
| 13 | 4321347940353 |
| 14 | 28435562985711 |
| 15 | 187111644664607 |
| 16 | 1231234858650427 |
| 17 | 8101804934566085 |
| 18 | 53311657284829409 |
[641,4219,28655,187203,1226781,8090191,53254665, 350253925,2304752967,15167443677,99803396861, 656712280793,4321347940353,28435562985711, 187111644664607,1231234858650427,8101804934566085, 53311657284829409] |