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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | -1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 8 |
| 8 | 13 |
| 9 | 20 |
| 10 | 38 |
| 11 | 86 |
| 12 | 215 |
| 13 | 526 |
| 14 | 1230 |
| 15 | 2762 |
| 16 | 6115 |
| 17 | 13670 |
| 18 | 31294 |
| 19 | 73258 |
| 20 | 173644 |
| 21 | 412612 |
| 22 | 978074 |
| 23 | 2313060 |
| 24 | 5472523 |
| 25 | 12989654 |
| 26 | 30974176 |
| 27 | 74174934 |
| 28 | 178173000 |
| 29 | 428776280 |
| 30 | 1033084378 |
| 31 | 2491843724 |
| 32 | 6018491615 |
| 33 | 14559411886 |
| 34 | 35279687544 |
[1,0,-1,1,2,5,8,13,20,38,86,215,526,1230,2762, 6115,13670,31294,73258,173644,412612,978074, 2313060,5472523,12989654,30974176,74174934, 178173000,428776280,1033084378,2491843724, 6018491615,14559411886,35279687544] |