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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 1 |
| 9 | 2 |
| 10 | 4 |
| 11 | 9 |
| 12 | 14 |
| 13 | 21 |
| 14 | 46 |
| 15 | 112 |
| 16 | 204 |
| 17 | 374 |
| 18 | 809 |
| 19 | 1586 |
| 20 | 3237 |
| 21 | 6385 |
| 22 | 12539 |
| 23 | 25637 |
| 24 | 50603 |
| 25 | 100891 |
| 26 | 20382 |
| 27 | 40281 |
| 28 | 81405 |
| 29 | 161718 |
| 30 | 323703 |
| 31 | 645928 |
[0,0,1,1,0,0,1,1,2,4,9,14,21,46,112,204,374,809, 1586,3237,6385,12539,25637,50603,100891,20382, 40281,81405,161718,323703,645928] |