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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 6 |
| 4 | 12 |
| 5 | 33 |
| 6 | 93 |
| 7 | 287 |
| 8 | 940 |
| 9 | 3309 |
| 10 | 12183 |
| 11 | 47133 |
| 12 | 190061 |
| 13 | 796405 |
| 14 | 3456405 |
| 15 | 15501183 |
| 16 | 71681170 |
| 17 | 341209173 |
| 18 | 1669411182 |
| 19 | 8384579797 |
| 20 | 43180474608 |
| 21 | 227797465130 |
| 22 | 1229915324579 |
| 23 | 6790642656907 |
| 24 | 38311482445514 |
| 25 | 220712337683628 |
| 26 | 1297542216770482 |
| 27 | 7779452884747298 |
[1,2,2,6,12,33,93,287,940,3309,12183,47133,190061, 796405,3456405,15501183,71681170,341209173, 1669411182,8384579797,43180474608,227797465130, 1229915324579,6790642656907,38311482445514, 220712337683628,1297542216770482,7779452884747298] |