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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 33 |
| 5 | 127 |
| 6 | 479 |
| 7 | 1987 |
| 8 | 8153 |
| 9 | 34531 |
| 10 | 149741 |
| 11 | 647735 |
| 12 | 2870859 |
| 13 | 12757149 |
| 14 | 57208157 |
| 15 | 259286825 |
| 16 | 1176744359 |
| 17 | 5390834697 |
| 18 | 24773267651 |
| 19 | 114338291417 |
| 20 | 530595471509 |
| 21 | 2466705308701 |
| 22 | 11521350667943 |
| 23 | 53941366645455 |
| 24 | 253217223758335 |
| 25 | 1192447189901931 |
| 26 | 5624336512312905 |
| 27 | 26601547030729237 |
[1,1,3,9,33,127,479,1987,8153,34531,149741,647735, 2870859,12757149,57208157,259286825,1176744359, 5390834697,24773267651,114338291417,530595471509, 2466705308701,11521350667943,53941366645455, 253217223758335,1192447189901931,5624336512312905, 26601547030729237] |