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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 0 |
| 2 | 8 |
| 3 | 13 |
| 4 | 42 |
| 5 | 102 |
| 6 | 275 |
| 7 | 712 |
| 8 | 1872 |
| 9 | 4893 |
| 10 | 12818 |
| 11 | 33550 |
| 12 | 87843 |
| 13 | 229968 |
| 14 | 602072 |
| 15 | 1576237 |
| 16 | 4126650 |
| 17 | 10803702 |
| 18 | 28284467 |
| 19 | 74049688 |
| 20 | 193864608 |
| 21 | 507544125 |
| 22 | 1328767778 |
| 23 | 3478759198 |
| 24 | 9107509827 |
| 25 | 23843770272 |
| 26 | 62423801000 |
| 27 | 163427632717 |
| 28 | 427859097162 |
| 29 | 1120149658758 |
[3,0,8,13,42,102,275,712,1872,4893,12818,33550, 87843,229968,602072,1576237,4126650,10803702, 28284467,74049688,193864608,507544125,1328767778, 3478759198,9107509827,23843770272,62423801000, 163427632717,427859097162,1120149658758] |