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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 55 |
| 6 | 187 |
| 7 | 664 |
| 8 | 2461 |
| 9 | 9313 |
| 10 | 36036 |
| 11 | 141602 |
| 12 | 564987 |
| 13 | 2283709 |
| 14 | 9329500 |
| 15 | 38470803 |
| 16 | 160040669 |
| 17 | 670687191 |
| 18 | 2829541104 |
| 19 | 12011760502 |
| 20 | 51268044607 |
| 21 | 219910158631 |
| 22 | 947691098759 |
| 23 | 4100976732537 |
| 24 | 17814653461222 |
| 25 | 77667474546123 |
| 26 | 339722451294319 |
| 27 | 1490525565318239 |
| 28 | 6558618691242851 |
[1,1,2,5,17,55,187,664,2461,9313,36036,141602, 564987,2283709,9329500,38470803,160040669, 670687191,2829541104,12011760502,51268044607, 219910158631,947691098759,4100976732537, 17814653461222,77667474546123,339722451294319, 1490525565318239,6558618691242851] |