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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 10 |
| 6 | 69 |
| 7 | 412 |
| 8 | 2291 |
| 9 | 12244 |
| 10 | 63886 |
| 11 | 328256 |
| 12 | 1669363 |
| 13 | 8429384 |
| 14 | 42349096 |
| 15 | 211982828 |
| 16 | 1058244079 |
| 17 | 5272285552 |
| 18 | 26227527576 |
| 19 | 130323237088 |
| 20 | 647013004499 |
| 21 | 3210128312122 |
| 22 | 15919166804461 |
| 23 | 78915323039268 |
| 24 | 391100149306301 |
[0,0,0,0,1,10,69,412,2291,12244,63886,328256, 1669363,8429384,42349096,211982828,1058244079, 5272285552,26227527576,130323237088,647013004499, 3210128312122,15919166804461,78915323039268, 391100149306301] |