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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 11 |
| 4 | 34 |
| 5 | 85 |
| 6 | 248 |
| 7 | 603 |
| 8 | 1630 |
| 9 | 4017 |
| 10 | 10308 |
| 11 | 24855 |
| 12 | 63210 |
| 13 | 150141 |
| 14 | 369936 |
| 15 | 882083 |
| 16 | 2135606 |
| 17 | 5023689 |
| 18 | 12064092 |
| 19 | 28167919 |
| 20 | 66828418 |
| 21 | 155569685 |
| 22 | 364983208 |
| 23 | 844175675 |
| 24 | 1971322574 |
| 25 | 4533662817 |
| 26 | 10498550260 |
| 27 | 24077361031 |
| 28 | 55432615194 |
| 29 | 126492183213 |
| 30 | 289997946944 |
[0,1,4,11,34,85,248,603,1630,4017,10308,24855, 63210,150141,369936,882083,2135606,5023689, 12064092,28167919,66828418,155569685,364983208, 844175675,1971322574,4533662817,10498550260, 24077361031,55432615194,126492183213,289997946944] |