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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 6 |
| 3 | 8 |
| 4 | 16 |
| 5 | 18 |
| 6 | 36 |
| 7 | 38 |
| 8 | 76 |
| 9 | 78 |
| 10 | 156 |
| 11 | 158 |
| 12 | 316 |
| 13 | 318 |
| 14 | 636 |
| 15 | 638 |
| 16 | 1276 |
| 17 | 1278 |
| 18 | 2556 |
| 19 | 2558 |
| 20 | 5116 |
| 21 | 5118 |
| 22 | 10236 |
| 23 | 10238 |
| 24 | 20476 |
| 25 | 20478 |
| 26 | 40956 |
| 27 | 40958 |
| 28 | 81916 |
| 29 | 81918 |
| 30 | 163836 |
| 31 | 163838 |
| 32 | 327676 |
| 33 | 327678 |
| 34 | 655356 |
| 35 | 655358 |
| 36 | 1310716 |
| 37 | 1310718 |
| 38 | 2621436 |
| 39 | 2621438 |
| 40 | 5242876 |
| 41 | 5242878 |
[1,3,6,8,16,18,36,38,76,78,156,158,316,318,636, 638,1276,1278,2556,2558,5116,5118,10236,10238, 20476,20478,40956,40958,81916,81918,163836,163838, 327676,327678,655356,655358,1310716,1310718, 2621436,2621438,5242876,5242878] |