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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 42 |
| 11 | 462 |
| 12 | 2772 |
| 13 | 12012 |
| 14 | 42042 |
| 15 | 126126 |
| 16 | 336336 |
| 17 | 816816 |
| 18 | 1837836 |
| 19 | 3879876 |
| 20 | 7759752 |
| 21 | 14814072 |
| 22 | 27159132 |
| 23 | 48050772 |
| 24 | 82372752 |
| 25 | 137287920 |
| 26 | 223092870 |
| 27 | 354323970 |
| 28 | 551170620 |
| 29 | 841260420 |
| 30 | 1261890630 |
| 31 | 1862790930 |
| 32 | 2709514080 |
| 33 | 3887563680 |
[0,0,0,0,0,0,0,0,0,0,42,462,2772,12012,42042, 126126,336336,816816,1837836,3879876,7759752, 14814072,27159132,48050772,82372752,137287920, 223092870,354323970,551170620,841260420, 1261890630,1862790930,2709514080,3887563680] |