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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 22 |
| 4 | 89 |
| 5 | 382 |
| 6 | 1702 |
| 7 | 7781 |
| 8 | 36229 |
| 9 | 170985 |
| 10 | 815280 |
| 11 | 3918288 |
| 12 | 18949282 |
| 13 | 92098505 |
| 14 | 449432199 |
| 15 | 2200447618 |
| 16 | 10803036616 |
| 17 | 53158537133 |
| 18 | 262081270998 |
| 19 | 1294220057191 |
| 20 | 6400089819063 |
| 21 | 31687261079330 |
| 22 | 157048357040647 |
| 23 | 779063981769830 |
| 24 | 3867712897176363 |
| 25 | 19214747051732096 |
| 26 | 95516560740768620 |
[1,2,6,22,89,382,1702,7781,36229,170985,815280, 3918288,18949282,92098505,449432199,2200447618, 10803036616,53158537133,262081270998, 1294220057191,6400089819063,31687261079330, 157048357040647,779063981769830,3867712897176363, 19214747051732096,95516560740768620] |