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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 3 |
| 6 | 3 |
| 7 | 12 |
| 8 | 30 |
| 9 | 45 |
| 10 | 75 |
| 11 | 192 |
| 12 | 436 |
| 13 | 798 |
| 14 | 1554 |
| 15 | 3542 |
| 16 | 7740 |
| 17 | 15543 |
| 18 | 32183 |
| 19 | 70794 |
| 20 | 153252 |
| 21 | 321431 |
| 22 | 684123 |
| 23 | 1491504 |
| 24 | 3232672 |
| 25 | 6928779 |
| 26 | 14957787 |
| 27 | 32615388 |
| 28 | 70991040 |
| 29 | 153985890 |
| 30 | 335256886 |
| 31 | 733206840 |
| 32 | 1603258134 |
| 33 | 3503385568 |
| 34 | 7671749664 |
| 35 | 16837946850 |
[1,0,0,1,3,3,3,12,30,45,75,192,436,798,1554,3542, 7740,15543,32183,70794,153252,321431,684123, 1491504,3232672,6928779,14957787,32615388, 70991040,153985890,335256886,733206840,1603258134, 3503385568,7671749664,16837946850] |