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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 12 |
| 5 | 30 |
| 6 | 76 |
| 7 | 196 |
| 8 | 518 |
| 9 | 1422 |
| 10 | 3915 |
| 11 | 10813 |
| 12 | 29964 |
| 13 | 83304 |
| 14 | 232323 |
| 15 | 649845 |
| 16 | 1822824 |
| 17 | 5147328 |
| 18 | 14727168 |
| 19 | 42171849 |
| 20 | 120870324 |
| 21 | 346757334 |
| 22 | 995742748 |
| 23 | 2862099185 |
| 24 | 8234447672 |
| 25 | 23713180780 |
| 26 | 68350541480 |
| 27 | 197188167735 |
[1,1,2,5,12,30,76,196,518,1422,3915,10813,29964, 83304,232323,649845,1822824,5147328,14727168, 42171849,120870324,346757334,995742748,2862099185, 8234447672,23713180780,68350541480,197188167735] |