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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 7 |
| 5 | 29 |
| 6 | 61 |
| 7 | 256 |
| 8 | 596 |
| 9 | 2507 |
| 10 | 6247 |
| 11 | 26197 |
| 12 | 68652 |
| 13 | 286232 |
| 14 | 780508 |
| 15 | 3231060 |
| 16 | 9102590 |
| 17 | 37392935 |
| 18 | 108279767 |
| 19 | 441342883 |
| 20 | 1308552478 |
| 21 | 5292781266 |
| 22 | 16018989626 |
| 23 | 64315663716 |
| 24 | 198213843417 |
| 25 | 790252270626 |
| 26 | 2474924176566 |
| 27 | 9802205324516 |
| 28 | 31142246753638 |
[1,1,1,4,7,29,61,256,596,2507,6247,26197,68652, 286232,780508,3231060,9102590,37392935,108279767, 441342883,1308552478,5292781266,16018989626, 64315663716,198213843417,790252270626, 2474924176566,9802205324516,31142246753638] |