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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 6 |
| 6 | 16 |
| 7 | 37 |
| 8 | 96 |
| 9 | 239 |
| 10 | 622 |
| 11 | 1607 |
| 12 | 4235 |
| 13 | 11185 |
| 14 | 29862 |
| 15 | 80070 |
| 16 | 216176 |
| 17 | 586218 |
| 18 | 1597578 |
| 19 | 4370721 |
| 20 | 12003882 |
| 21 | 33077327 |
| 22 | 91433267 |
| 23 | 253454781 |
| 24 | 704429853 |
| 25 | 1962537755 |
| 26 | 5479855546 |
| 27 | 15332668869 |
| 28 | 42983656210 |
| 29 | 120716987723 |
| 30 | 339596063606 |
| 31 | 956840683968 |
[0,1,1,3,6,16,37,96,239,622,1607,4235,11185,29862, 80070,216176,586218,1597578,4370721,12003882, 33077327,91433267,253454781,704429853,1962537755, 5479855546,15332668869,42983656210,120716987723, 339596063606,956840683968] |