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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 4 |
| 6 | 10 |
| 7 | 20 |
| 8 | 42 |
| 9 | 84 |
| 10 | 166 |
| 11 | 320 |
| 12 | 608 |
| 13 | 1140 |
| 14 | 2116 |
| 15 | 3892 |
| 16 | 7102 |
| 17 | 12868 |
| 18 | 23170 |
| 19 | 41488 |
| 20 | 73918 |
| 21 | 131104 |
| 22 | 231578 |
| 23 | 407520 |
| 24 | 714672 |
| 25 | 1249368 |
| 26 | 2177736 |
| 27 | 3785688 |
| 28 | 6564362 |
| 29 | 11355940 |
| 30 | 19602154 |
| 31 | 33767228 |
| 32 | 58056786 |
| 33 | 99638364 |
| 34 | 170711134 |
| 35 | 292011872 |
| 36 | 498747632 |
[0,0,0,0,2,4,10,20,42,84,166,320,608,1140,2116, 3892,7102,12868,23170,41488,73918,131104,231578, 407520,714672,1249368,2177736,3785688,6564362, 11355940,19602154,33767228,58056786,99638364, 170711134,292011872,498747632] |