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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 3 |
| 10 | 8 |
| 11 | 20 |
| 12 | 48 |
| 13 | 112 |
| 14 | 256 |
| 15 | 684 |
| 16 | 1696 |
| 17 | 3840 |
| 18 | 8575 |
| 19 | 18939 |
| 20 | 41452 |
| 21 | 90046 |
| 22 | 206952 |
| 23 | 466731 |
| 24 | 1037736 |
| 25 | 2233540 |
| 26 | 4782408 |
| 27 | 10194180 |
| 28 | 21638844 |
| 29 | 47278465 |
| 30 | 102437882 |
| 31 | 220088444 |
| 32 | 470234676 |
[0,0,0,0,0,0,0,0,1,3,8,20,48,112,256,684,1696, 3840,8575,18939,41452,90046,206952,466731,1037736, 2233540,4782408,10194180,21638844,47278465, 102437882,220088444,470234676] |