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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 11 |
| 8 | 37 |
| 9 | 109 |
| 10 | 287 |
| 11 | 698 |
| 12 | 1617 |
| 13 | 3642 |
| 14 | 7985 |
| 15 | 17208 |
| 16 | 36620 |
| 17 | 77093 |
| 18 | 161027 |
| 19 | 334205 |
| 20 | 690080 |
| 21 | 1418917 |
| 22 | 2907655 |
| 23 | 5941148 |
| 24 | 12110674 |
[0,0,0,0,0,1,11,37,109,287,698,1617,3642,7985, 17208,36620,77093,161027,334205,690080,1418917, 2907655,5941148,12110674] |