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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 17 |
| 2 | 109 |
| 3 | 755 |
| 4 | 5473 |
| 5 | 40787 |
| 6 | 309529 |
| 7 | 2379275 |
| 8 | 18463393 |
| 9 | 144315107 |
| 10 | 1134267049 |
| 11 | 8952908795 |
| 12 | 70896790513 |
| 13 | 562818102227 |
| 14 | 4476415458169 |
| 15 | 35654571422315 |
| 16 | 284296129664833 |
| 17 | 2268726602270147 |
| 18 | 18115958853570889 |
| 19 | 144724548978127835 |
[3,17,109,755,5473,40787,309529,2379275,18463393, 144315107,1134267049,8952908795,70896790513, 562818102227,4476415458169,35654571422315, 284296129664833,2268726602270147, 18115958853570889,144724548978127835] |