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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | 0 |
| 5 | 1 |
| 6 | 0 |
| 7 | 3 |
| 8 | 1 |
| 9 | 7 |
| 10 | 4 |
| 11 | 19 |
| 12 | 17 |
| 13 | 63 |
| 14 | 77 |
| 15 | 217 |
| 16 | 326 |
| 17 | 815 |
| 18 | 1435 |
| 19 | 3533 |
| 20 | 7227 |
| 21 | 17709 |
| 22 | 39704 |
| 23 | 97010 |
| 24 | 228123 |
| 25 | 561216 |
| 26 | 1366962 |
| 27 | 3423504 |
| 28 | 8601350 |
| 29 | 22000341 |
| 30 | 56612480 |
| 31 | 147248370 |
| 32 | 384885631 |
[1,1,-1,1,0,1,0,3,1,7,4,19,17,63,77,217,326,815, 1435,3533,7227,17709,39704,97010,228123,561216, 1366962,3423504,8601350,22000341,56612480, 147248370,384885631] |