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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 1 |
| 6 | 6 |
| 7 | 7 |
| 8 | 37 |
| 9 | 47 |
| 10 | 242 |
| 11 | 324 |
| 12 | 1658 |
| 13 | 2300 |
| 14 | 11764 |
| 15 | 16741 |
| 16 | 85741 |
| 17 | 124383 |
| 18 | 638250 |
| 19 | 939880 |
| 20 | 4832446 |
| 21 | 7202214 |
| 22 | 37101556 |
| 23 | 55842670 |
| 24 | 288180066 |
| 25 | 437325262 |
| 26 | 2260516372 |
| 27 | 3454370352 |
| 28 | 17881862308 |
| 29 | 27489383818 |
| 30 | 142491830992 |
| 31 | 220185726817 |
[0,0,0,1,1,6,7,37,47,242,324,1658,2300,11764, 16741,85741,124383,638250,939880,4832446,7202214, 37101556,55842670,288180066,437325262,2260516372, 3454370352,17881862308,27489383818,142491830992, 220185726817] |