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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 3 |
| 3 | 1 |
| 4 | 14 |
| 5 | 4 |
| 6 | 57 |
| 7 | 22 |
| 8 | 240 |
| 9 | 109 |
| 10 | 896 |
| 11 | 351 |
| 12 | 3855 |
| 13 | 1655 |
| 14 | 14371 |
| 15 | 6057 |
| 16 | 62218 |
| 17 | 24672 |
| 18 | 232343 |
| 19 | 90451 |
| 20 | 989205 |
| 21 | 410308 |
| 22 | 3701811 |
| 23 | 1522381 |
| 24 | 15864320 |
| 25 | 6308061 |
| 26 | 59454216 |
| 27 | 23120985 |
| 28 | 253629056 |
| 29 | 105696837 |
| 30 | 945955884 |
| 31 | 386457921 |
| 32 | 4065281594 |
| 33 | 1611010322 |
| 34 | 15213321794 |
[1,0,3,1,14,4,57,22,240,109,896,351,3855,1655, 14371,6057,62218,24672,232343,90451,989205,410308, 3701811,1522381,15864320,6308061,59454216, 23120985,253629056,105696837,945955884,386457921, 4065281594,1611010322,15213321794] |