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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 3 |
| 3 | 8 |
| 4 | 18 |
| 5 | 48 |
| 6 | 109 |
| 7 | 264 |
| 8 | 594 |
| 9 | 1360 |
| 10 | 2988 |
| 11 | 6552 |
| 12 | 14115 |
| 13 | 30048 |
| 14 | 63288 |
| 15 | 131800 |
| 16 | 271953 |
| 17 | 555792 |
| 18 | 1126583 |
| 19 | 2264472 |
| 20 | 4518051 |
| 21 | 8948544 |
| 22 | 17603781 |
| 23 | 34405272 |
| 24 | 66828247 |
| 25 | 129040704 |
| 26 | 247765665 |
| 27 | 473160696 |
| 28 | 898924929 |
| 29 | 1699331808 |
| 30 | 3197083220 |
| 31 | 5987288352 |
| 32 | 11162934948 |
[1,0,3,8,18,48,109,264,594,1360,2988,6552,14115, 30048,63288,131800,271953,555792,1126583,2264472, 4518051,8948544,17603781,34405272,66828247, 129040704,247765665,473160696,898924929, 1699331808,3197083220,5987288352,11162934948] |