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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | 2 |
| 6 | 0 |
| 7 | 3 |
| 8 | 2 |
| 9 | 0 |
| 10 | 4 |
| 11 | 18 |
| 12 | 0 |
| 13 | 5 |
| 14 | 84 |
| 15 | 6 |
| 16 | 0 |
| 17 | 6 |
| 18 | 300 |
| 19 | 144 |
| 20 | 0 |
| 21 | 7 |
| 22 | 930 |
| 23 | 1500 |
| 24 | 24 |
| 25 | 0 |
| 26 | 8 |
| 27 | 2646 |
| 28 | 10800 |
| 29 | 1200 |
| 30 | 0 |
| 31 | 9 |
| 32 | 7112 |
| 33 | 63210 |
| 34 | 23400 |
| 35 | 120 |
| 36 | 0 |
| 37 | 10 |
| 38 | 18360 |
| 39 | 324576 |
| 40 | 294000 |
| 41 | 10800 |
| 42 | 0 |
| 43 | 11 |
| 44 | 45990 |
| 45 | 1524600 |
| 46 | 2857680 |
| 47 | 352800 |
| 48 | 720 |
| 49 | 0 |
| 50 | 12 |
| 51 | 112530 |
| 52 | 6717600 |
| 53 | 23496480 |
| 54 | 7056000 |
| 55 | 105840 |
[1,0,0,1,0,2,0,3,2,0,4,18,0,5,84,6,0,6,300,144,0, 7,930,1500,24,0,8,2646,10800,1200,0,9,7112,63210, 23400,120,0,10,18360,324576,294000,10800,0,11, 45990,1524600,2857680,352800,720,0,12,112530, 6717600,23496480,7056000,105840] |