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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 20 |
| 6 | 47 |
| 7 | 118 |
| 8 | 280 |
| 9 | 681 |
| 10 | 1640 |
| 11 | 3963 |
| 12 | 9523 |
| 13 | 23004 |
| 14 | 55377 |
| 15 | 133477 |
| 16 | 321597 |
| 17 | 775054 |
| 18 | 1867304 |
| 19 | 4499934 |
| 20 | 10842847 |
| 21 | 26127768 |
| 22 | 62958232 |
| 23 | 151708512 |
| 24 | 365562567 |
| 25 | 880881465 |
| 26 | 2122617010 |
| 27 | 5114772619 |
| 28 | 12324827128 |
| 29 | 29698572295 |
| 30 | 71563264162 |
| 31 | 172442689864 |
| 32 | 415527172616 |
[1,1,3,8,20,47,118,280,681,1640,3963,9523,23004, 55377,133477,321597,775054,1867304,4499934, 10842847,26127768,62958232,151708512,365562567, 880881465,2122617010,5114772619,12324827128, 29698572295,71563264162,172442689864,415527172616] |