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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 1 |
| 3 | -1 |
| 4 | 2 |
| 5 | 0 |
| 6 | 4 |
| 7 | 3 |
| 8 | 11 |
| 9 | 17 |
| 10 | 40 |
| 11 | 74 |
| 12 | 154 |
| 13 | 301 |
| 14 | 609 |
| 15 | 1211 |
| 16 | 2430 |
| 17 | 4852 |
| 18 | 9712 |
| 19 | 19415 |
| 20 | 38839 |
| 21 | 77669 |
| 22 | 155348 |
| 23 | 310686 |
| 24 | 621382 |
| 25 | 1242753 |
| 26 | 2485517 |
| 27 | 4971023 |
| 28 | 9942058 |
| 29 | 19884104 |
| 30 | 39768220 |
| 31 | 79536427 |
| 32 | 159072867 |
| 33 | 318145721 |
| 34 | 636291456 |
| 35 | 1272582898 |
| 36 | 2545165810 |
[1,-1,1,-1,2,0,4,3,11,17,40,74,154,301,609,1211, 2430,4852,9712,19415,38839,77669,155348,310686, 621382,1242753,2485517,4971023,9942058,19884104, 39768220,79536427,159072867,318145721,636291456, 1272582898,2545165810] |