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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 17 |
| 5 | 43 |
| 6 | 111 |
| 7 | 289 |
| 8 | 755 |
| 9 | 1975 |
| 10 | 5169 |
| 11 | 13531 |
| 12 | 35423 |
| 13 | 92737 |
| 14 | 242787 |
| 15 | 635623 |
| 16 | 1664081 |
| 17 | 4356619 |
| 18 | 11405775 |
| 19 | 29860705 |
| 20 | 78176339 |
| 21 | 204668311 |
| 22 | 535828593 |
| 23 | 1402817467 |
| 24 | 3672623807 |
| 25 | 9615053953 |
| 26 | 25172538051 |
| 27 | 65902560199 |
[1,1,3,7,17,43,111,289,755,1975,5169,13531,35423, 92737,242787,635623,1664081,4356619,11405775, 29860705,78176339,204668311,535828593,1402817467, 3672623807,9615053953,25172538051,65902560199] |