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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | 10 |
| 7 | 44 |
| 8 | 190 |
| 9 | 856 |
| 10 | 4106 |
| 11 | 21092 |
| 12 | 115886 |
| 13 | 678426 |
| 14 | 4213364 |
| 15 | 27644060 |
| 16 | 190898712 |
| 17 | 1382957558 |
| 18 | 10480140550 |
| 19 | 82864867220 |
| 20 | 682076801978 |
| 21 | 5832742198292 |
| 22 | 51724158224426 |
| 23 | 474869816139040 |
| 24 | 4506715738418666 |
[1,1,0,0,0,2,10,44,190,856,4106,21092,115886, 678426,4213364,27644060,190898712,1382957558, 10480140550,82864867220,682076801978, 5832742198292,51724158224426,474869816139040, 4506715738418666] |