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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 7 |
| 3 | 15 |
| 4 | 35 |
| 5 | 79 |
| 6 | 183 |
| 7 | 427 |
| 8 | 995 |
| 9 | 2319 |
| 10 | 5411 |
| 11 | 12623 |
| 12 | 29451 |
| 13 | 68719 |
| 14 | 160343 |
| 15 | 374131 |
| 16 | 872971 |
| 17 | 2036931 |
| 18 | 4752839 |
| 19 | 11089955 |
| 20 | 25876559 |
| 21 | 60378635 |
| 22 | 140883479 |
| 23 | 328728115 |
| 24 | 767032267 |
| 25 | 1789741955 |
| 26 | 4176064559 |
| 27 | 9744150635 |
| 28 | 22736351479 |
| 29 | 53051486783 |
[3,7,15,35,79,183,427,995,2319,5411,12623,29451, 68719,160343,374131,872971,2036931,4752839, 11089955,25876559,60378635,140883479,328728115, 767032267,1789741955,4176064559,9744150635, 22736351479,53051486783] |