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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 7 |
| 8 | 11 |
| 9 | 26 |
| 10 | 52 |
| 11 | 120 |
| 12 | 266 |
| 13 | 640 |
| 14 | 1509 |
| 15 | 3702 |
| 16 | 9090 |
| 17 | 22781 |
| 18 | 57452 |
| 19 | 146783 |
| 20 | 377357 |
| 21 | 978342 |
| 22 | 2550611 |
| 23 | 6690242 |
| 24 | 17633855 |
| 25 | 46705333 |
| 26 | 124227015 |
| 27 | 331757697 |
| 28 | 889207207 |
| 29 | 2391478247 |
| 30 | 6451880415 |
| 31 | 17457214729 |
| 32 | 47363110968 |
[0,1,0,1,1,2,3,7,11,26,52,120,266,640,1509,3702, 9090,22781,57452,146783,377357,978342,2550611, 6690242,17633855,46705333,124227015,331757697, 889207207,2391478247,6451880415,17457214729, 47363110968] |