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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 20 |
| 5 | 41 |
| 6 | 85 |
| 7 | 173 |
| 8 | 349 |
| 9 | 701 |
| 10 | 1405 |
| 11 | 2813 |
| 12 | 5629 |
| 13 | 11261 |
| 14 | 22525 |
| 15 | 45053 |
| 16 | 90113 |
| 17 | 180232 |
| 18 | 360466 |
| 19 | 720937 |
| 20 | 1441877 |
| 21 | 2883761 |
| 22 | 5767525 |
| 23 | 11535053 |
| 24 | 23070112 |
| 25 | 46140228 |
| 26 | 92280457 |
| 27 | 184560921 |
| 28 | 369121849 |
| 29 | 738243700 |
| 30 | 1476487402 |
| 31 | 2952974809 |
| 32 | 5905949620 |
| 33 | 11811899241 |
[1,4,9,20,41,85,173,349,701,1405,2813,5629,11261, 22525,45053,90113,180232,360466,720937,1441877, 2883761,5767525,11535053,23070112,46140228, 92280457,184560921,369121849,738243700,1476487402, 2952974809,5905949620,11811899241] |