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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 22 |
| 4 | 114 |
| 5 | 308 |
| 6 | 1717 |
| 7 | 4902 |
| 8 | 28526 |
| 9 | 84284 |
| 10 | 504410 |
| 11 | 1525500 |
| 12 | 9311140 |
| 13 | 28638504 |
| 14 | 177367949 |
| 15 | 552532742 |
| 16 | 3460680278 |
| 17 | 10888711788 |
| 18 | 68810154286 |
| 19 | 218247846932 |
| 20 | 1389230689596 |
| 21 | 4435391806552 |
| 22 | 28403131135554 |
| 23 | 91183193910620 |
| 24 | 586877613154252 |
| 25 | 1892886293567192 |
[1,2,9,22,114,308,1717,4902,28526,84284,504410, 1525500,9311140,28638504,177367949,552532742, 3460680278,10888711788,68810154286,218247846932, 1389230689596,4435391806552,28403131135554, 91183193910620,586877613154252,1892886293567192] |