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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 23 |
| 5 | 66 |
| 6 | 190 |
| 7 | 547 |
| 8 | 1575 |
| 9 | 4535 |
| 10 | 13058 |
| 11 | 37599 |
| 12 | 108262 |
| 13 | 311728 |
| 14 | 897585 |
| 15 | 2584493 |
| 16 | 7441751 |
| 17 | 21427668 |
| 18 | 61698511 |
| 19 | 177653782 |
| 20 | 511533678 |
| 21 | 1472902523 |
| 22 | 4241053787 |
| 23 | 12211627683 |
| 24 | 35161980526 |
| 25 | 101244887791 |
| 26 | 291523035690 |
| 27 | 839407126544 |
| 28 | 2416976491841 |
| 29 | 6959406439833 |
[1,1,3,8,23,66,190,547,1575,4535,13058,37599, 108262,311728,897585,2584493,7441751,21427668, 61698511,177653782,511533678,1472902523, 4241053787,12211627683,35161980526,101244887791, 291523035690,839407126544,2416976491841, 6959406439833] |