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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 7 |
| 5 | 17 |
| 6 | 42 |
| 7 | 109 |
| 8 | 285 |
| 9 | 757 |
| 10 | 2036 |
| 11 | 5535 |
| 12 | 15184 |
| 13 | 41955 |
| 14 | 116657 |
| 15 | 326111 |
| 16 | 915887 |
| 17 | 2582803 |
| 18 | 7309820 |
| 19 | 20754669 |
| 20 | 59098040 |
| 21 | 168715374 |
| 22 | 482785532 |
| 23 | 1384458512 |
| 24 | 3977880795 |
| 25 | 11449846073 |
| 26 | 33011244523 |
| 27 | 95319968562 |
| 28 | 275624005481 |
| 29 | 798027643777 |
| 30 | 2313383506681 |
[1,1,3,7,17,42,109,285,757,2036,5535,15184,41955, 116657,326111,915887,2582803,7309820,20754669, 59098040,168715374,482785532,1384458512, 3977880795,11449846073,33011244523,95319968562, 275624005481,798027643777,2313383506681] |