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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 2 |
| 8 | 12 |
| 9 | 42 |
| 10 | 63 |
| 11 | 168 |
| 12 | 378 |
| 13 | 504 |
| 14 | 1014 |
| 15 | 1914 |
| 16 | 2420 |
| 17 | 4620 |
| 18 | 9295 |
| 19 | 12012 |
| 20 | 27027 |
| 21 | 63083 |
| 22 | 84119 |
| 23 | 199304 |
| 24 | 456484 |
| 25 | 601664 |
| 26 | 1339464 |
| 27 | 2896664 |
| 28 | 3755844 |
| 29 | 8093214 |
| 30 | 17441739 |
| 31 | 22591800 |
| 32 | 49876200 |
| 33 | 111029050 |
| 34 | 144780009 |
[0,0,0,0,0,1,2,12,42,63,168,378,504,1014,1914, 2420,4620,9295,12012,27027,63083,84119,199304, 456484,601664,1339464,2896664,3755844,8093214, 17441739,22591800,49876200,111029050,144780009] |