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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 0 |
| 7 | 2 |
| 8 | 10 |
| 9 | 15 |
| 10 | 0 |
| 11 | 6 |
| 12 | 40 |
| 13 | 105 |
| 14 | 105 |
| 15 | 0 |
| 16 | 24 |
| 17 | 196 |
| 18 | 700 |
| 19 | 1260 |
| 20 | 945 |
| 21 | 0 |
| 22 | 120 |
| 23 | 1148 |
| 24 | 5068 |
| 25 | 12600 |
| 26 | 17325 |
| 27 | 10395 |
| 28 | 0 |
| 29 | 720 |
| 30 | 7848 |
| 31 | 40740 |
| 32 | 126280 |
| 33 | 242550 |
| 34 | 270270 |
| 35 | 135135 |
| 36 | 0 |
| 37 | 5040 |
| 38 | 61416 |
| 39 | 363660 |
| 40 | 1332100 |
| 41 | 3213210 |
| 42 | 5045040 |
| 43 | 4729725 |
| 44 | 2027025 |
| 45 | 0 |
| 46 | 40320 |
| 47 | 541728 |
| 48 | 3584856 |
| 49 | 15020720 |
| 50 | 43022980 |
| 51 | 85345260 |
| 52 | 113513400 |
| 53 | 91891800 |
| 54 | 34459425 |
[1,0,1,0,1,3,0,2,10,15,0,6,40,105,105,0,24,196, 700,1260,945,0,120,1148,5068,12600,17325,10395,0, 720,7848,40740,126280,242550,270270,135135,0,5040, 61416,363660,1332100,3213210,5045040,4729725, 2027025,0,40320,541728,3584856,15020720,43022980, 85345260,113513400,91891800,34459425] |