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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 0 |
| 4 | 10 |
| 5 | 0 |
| 6 | 44 |
| 7 | 28 |
| 8 | 202 |
| 9 | 252 |
| 10 | 872 |
| 11 | 1364 |
| 12 | 3748 |
| 13 | 6552 |
| 14 | 15500 |
| 15 | 29040 |
| 16 | 63562 |
| 17 | 122400 |
| 18 | 257588 |
| 19 | 504868 |
| 20 | 1038520 |
| 21 | 2054416 |
| 22 | 4171796 |
| 23 | 8294444 |
| 24 | 16728580 |
| 25 | 33349800 |
| 26 | 67002392 |
| 27 | 133775964 |
| 28 | 268207012 |
| 29 | 535920696 |
| 30 | 1073250704 |
| 31 | 2145452092 |
| 32 | 4293920842 |
| 33 | 8585610704 |
| 34 | 17177640992 |
| 35 | 34350563968 |
[0,2,0,10,0,44,28,202,252,872,1364,3748,6552, 15500,29040,63562,122400,257588,504868,1038520, 2054416,4171796,8294444,16728580,33349800, 67002392,133775964,268207012,535920696,1073250704, 2145452092,4293920842,8585610704,17177640992, 34350563968] |