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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 19 |
| 3 | 121 |
| 4 | 771 |
| 5 | 4913 |
| 6 | 31307 |
| 7 | 199497 |
| 8 | 1271251 |
| 9 | 8100769 |
| 10 | 51620379 |
| 11 | 328939577 |
| 12 | 2096095523 |
| 13 | 13356910353 |
| 14 | 85113990379 |
| 15 | 542370291241 |
| 16 | 3456136077171 |
| 17 | 22023471375233 |
| 18 | 140339755317947 |
| 19 | 894284401724697 |
| 20 | 5698631790801091 |
| 21 | 36313284928708849 |
| 22 | 231398467337757579 |
[3,19,121,771,4913,31307,199497,1271251,8100769, 51620379,328939577,2096095523,13356910353, 85113990379,542370291241,3456136077171, 22023471375233,140339755317947,894284401724697, 5698631790801091,36313284928708849, 231398467337757579] |