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| n | a(n) |
|---|---|
| 0 | -1 |
| 1 | 2 |
| 2 | -1 |
| 3 | 1 |
| 4 | 4 |
| 5 | -1 |
| 6 | 4 |
| 7 | 3 |
| 8 | 6 |
| 9 | -1 |
| 10 | 3 |
| 11 | 16 |
| 12 | 6 |
| 13 | 8 |
| 14 | -1 |
| 15 | 6 |
| 16 | 15 |
| 17 | 40 |
| 18 | 10 |
| 19 | 10 |
| 20 | -1 |
| 21 | 5 |
| 22 | 36 |
| 23 | 45 |
| 24 | 80 |
| 25 | 15 |
| 26 | 12 |
| 27 | -1 |
| 28 | 8 |
| 29 | 35 |
| 30 | 126 |
| 31 | 105 |
| 32 | 140 |
| 33 | 21 |
| 34 | 14 |
| 35 | -1 |
| 36 | 7 |
| 37 | 64 |
| 38 | 140 |
| 39 | 336 |
| 40 | 210 |
| 41 | 224 |
| 42 | 28 |
| 43 | 16 |
| 44 | -1 |
| 45 | 10 |
| 46 | 63 |
| 47 | 288 |
| 48 | 420 |
| 49 | 756 |
| 50 | 378 |
| 51 | 336 |
| 52 | 36 |
| 53 | 18 |
| 54 | -1 |
| 55 | 9 |
| 56 | 100 |
| 57 | 315 |
| 58 | 960 |
| 59 | 1050 |
| 60 | 1512 |
| 61 | 630 |
| 62 | 480 |
| 63 | 45 |
| 64 | 20 |
| 65 | -1 |
[-1,2,-1,1,4,-1,4,3,6,-1,3,16,6,8,-1,6,15,40,10, 10,-1,5,36,45,80,15,12,-1,8,35,126,105,140,21,14, -1,7,64,140,336,210,224,28,16,-1,10,63,288,420, 756,378,336,36,18,-1,9,100,315,960,1050,1512,630, 480,45,20,-1] |