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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 4 |
| 4 | 0 |
| 5 | 0 |
| 6 | 10 |
| 7 | 0 |
| 8 | 0 |
| 9 | 20 |
| 10 | 0 |
| 11 | 1 |
| 12 | 35 |
| 13 | 0 |
| 14 | 8 |
| 15 | 56 |
| 16 | 0 |
| 17 | 36 |
| 18 | 84 |
| 19 | 0 |
| 20 | 120 |
| 21 | 120 |
| 22 | 1 |
| 23 | 330 |
| 24 | 165 |
| 25 | 12 |
| 26 | 792 |
| 27 | 220 |
| 28 | 78 |
| 29 | 1716 |
| 30 | 286 |
| 31 | 364 |
| 32 | 3432 |
| 33 | 365 |
| 34 | 1365 |
| 35 | 6435 |
| 36 | 471 |
| 37 | 4368 |
| 38 | 11440 |
| 39 | 696 |
| 40 | 12376 |
| 41 | 19448 |
| 42 | 1496 |
| 43 | 31824 |
| 44 | 31825 |
| 45 | 4692 |
| 46 | 75582 |
| 47 | 50408 |
| 48 | 16473 |
| 49 | 167960 |
| 50 | 77730 |
| 51 | 55404 |
| 52 | 352716 |
[1,0,0,4,0,0,10,0,0,20,0,1,35,0,8,56,0,36,84,0, 120,120,1,330,165,12,792,220,78,1716,286,364,3432, 365,1365,6435,471,4368,11440,696,12376,19448,1496, 31824,31825,4692,75582,50408,16473,167960,77730, 55404,352716] |