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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 7 |
| 7 | 16 |
| 8 | 40 |
| 9 | 92 |
| 10 | 209 |
| 11 | 468 |
| 12 | 1027 |
| 13 | 2242 |
| 14 | 4832 |
| 15 | 10360 |
| 16 | 22049 |
| 17 | 46694 |
| 18 | 98419 |
| 19 | 206588 |
| 20 | 432132 |
| 21 | 900980 |
| 22 | 1873297 |
| 23 | 3884904 |
| 24 | 8038295 |
| 25 | 16597478 |
| 26 | 34205700 |
| 27 | 70372728 |
| 28 | 144550977 |
| 29 | 296486538 |
| 30 | 607301551 |
| 31 | 1242406568 |
| 32 | 2538762208 |
| 33 | 5182207180 |
[0,0,0,0,1,2,7,16,40,92,209,468,1027,2242,4832, 10360,22049,46694,98419,206588,432132,900980, 1873297,3884904,8038295,16597478,34205700, 70372728,144550977,296486538,607301551,1242406568, 2538762208,5182207180] |