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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 28 |
| 5 | 85 |
| 6 | 275 |
| 7 | 924 |
| 8 | 3161 |
| 9 | 11123 |
| 10 | 40356 |
| 11 | 148994 |
| 12 | 555317 |
| 13 | 2099039 |
| 14 | 8057473 |
| 15 | 31247345 |
| 16 | 122019881 |
| 17 | 480549169 |
| 18 | 1909455313 |
| 19 | 7638161881 |
| 20 | 30713415080 |
| 21 | 124209720711 |
| 22 | 505237712256 |
| 23 | 2064851613757 |
| 24 | 8472358195113 |
| 25 | 34907360687287 |
| 26 | 144413933270171 |
| 27 | 599556168765568 |
| 28 | 2496836471032115 |
[1,2,4,10,28,85,275,924,3161,11123,40356,148994, 555317,2099039,8057473,31247345,122019881, 480549169,1909455313,7638161881,30713415080, 124209720711,505237712256,2064851613757, 8472358195113,34907360687287,144413933270171, 599556168765568,2496836471032115] |