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| n | a(n) |
|---|---|
| 0 | 7 |
| 1 | 31 |
| 2 | 103 |
| 3 | 303 |
| 4 | 831 |
| 5 | 2175 |
| 6 | 5503 |
| 7 | 13567 |
| 8 | 32767 |
| 9 | 77823 |
| 10 | 182271 |
| 11 | 421887 |
| 12 | 966655 |
| 13 | 2195455 |
| 14 | 4947967 |
| 15 | 11075583 |
| 16 | 24641535 |
| 17 | 54525951 |
| 18 | 120061951 |
| 19 | 263192575 |
| 20 | 574619647 |
| 21 | 1249902591 |
| 22 | 2709520383 |
| 23 | 5855248383 |
| 24 | 12616466431 |
| 25 | 27111981055 |
| 26 | 58116276223 |
| 27 | 124285616127 |
[7,31,103,303,831,2175,5503,13567,32767,77823, 182271,421887,966655,2195455,4947967,11075583, 24641535,54525951,120061951,263192575,574619647, 1249902591,2709520383,5855248383,12616466431, 27111981055,58116276223,124285616127] |