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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 42 |
| 5 | 132 |
| 6 | 427 |
| 7 | 1402 |
| 8 | 4629 |
| 9 | 15290 |
| 10 | 50412 |
| 11 | 165816 |
| 12 | 544253 |
| 13 | 1783602 |
| 14 | 5839313 |
| 15 | 19106766 |
| 16 | 62504002 |
| 17 | 204457540 |
| 18 | 668825279 |
| 19 | 2188016442 |
| 20 | 7158417217 |
| 21 | 23421034442 |
| 22 | 76632061852 |
| 23 | 250740203864 |
| 24 | 820430583305 |
| 25 | 2684486330562 |
| 26 | 8783760256301 |
| 27 | 28740810537518 |
| 28 | 94040879244602 |
[1,2,5,14,42,132,427,1402,4629,15290,50412,165816, 544253,1783602,5839313,19106766,62504002, 204457540,668825279,2188016442,7158417217, 23421034442,76632061852,250740203864,820430583305, 2684486330562,8783760256301,28740810537518, 94040879244602] |