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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 7 |
| 5 | 12 |
| 6 | 22 |
| 7 | 42 |
| 8 | 76 |
| 9 | 139 |
| 10 | 267 |
| 11 | 516 |
| 12 | 999 |
| 13 | 1951 |
| 14 | 3824 |
| 15 | 7486 |
| 16 | 14681 |
| 17 | 28797 |
| 18 | 56191 |
| 19 | 108921 |
| 20 | 210746 |
| 21 | 410016 |
| 22 | 804971 |
| 23 | 1591352 |
| 24 | 3153835 |
| 25 | 6249154 |
| 26 | 12380967 |
| 27 | 24553237 |
| 28 | 48731373 |
| 29 | 96622022 |
| 30 | 191012244 |
| 31 | 376293782 |
| 32 | 739671592 |
| 33 | 1454332766 |
| 34 | 2867413428 |
| 35 | 5678310305 |
[0,2,4,7,12,22,42,76,139,267,516,999,1951,3824, 7486,14681,28797,56191,108921,210746,410016, 804971,1591352,3153835,6249154,12380967,24553237, 48731373,96622022,191012244,376293782,739671592, 1454332766,2867413428,5678310305] |