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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 20 |
| 5 | 50 |
| 6 | 115 |
| 7 | 251 |
| 8 | 530 |
| 9 | 1096 |
| 10 | 2237 |
| 11 | 4529 |
| 12 | 9124 |
| 13 | 18326 |
| 14 | 36743 |
| 15 | 73591 |
| 16 | 147302 |
| 17 | 294740 |
| 18 | 589633 |
| 19 | 1179437 |
| 20 | 2359064 |
| 21 | 4718338 |
| 22 | 9436907 |
| 23 | 18874067 |
| 24 | 37748410 |
| 25 | 75497120 |
| 26 | 150994565 |
| 27 | 301989481 |
| 28 | 603979340 |
| 29 | 1207959086 |
[1,2,7,20,50,115,251,530,1096,2237,4529,9124, 18326,36743,73591,147302,294740,589633,1179437, 2359064,4718338,9436907,18874067,37748410, 75497120,150994565,301989481,603979340,1207959086] |