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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 29 |
| 6 | 77 |
| 7 | 201 |
| 8 | 525 |
| 9 | 1361 |
| 10 | 3525 |
| 11 | 9097 |
| 12 | 23453 |
| 13 | 60353 |
| 14 | 155189 |
| 15 | 398649 |
| 16 | 1023501 |
| 17 | 2626289 |
| 18 | 6736677 |
| 19 | 17274601 |
| 20 | 44286845 |
| 21 | 113516321 |
| 22 | 290925845 |
| 23 | 745515417 |
| 24 | 1910267373 |
| 25 | 4894426193 |
| 26 | 12539689989 |
| 27 | 32125783369 |
| 28 | 82301320541 |
| 29 | 210838008449 |
[1,2,4,11,29,77,201,525,1361,3525,9097,23453, 60353,155189,398649,1023501,2626289,6736677, 17274601,44286845,113516321,290925845,745515417, 1910267373,4894426193,12539689989,32125783369, 82301320541,210838008449] |