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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | -1 |
| 6 | -2 |
| 7 | 0 |
| 8 | 2 |
| 9 | 3 |
| 10 | 0 |
| 11 | -3 |
| 12 | -4 |
| 13 | 0 |
| 14 | 4 |
| 15 | 5 |
| 16 | 0 |
| 17 | -5 |
| 18 | -6 |
| 19 | 0 |
| 20 | 6 |
| 21 | 7 |
| 22 | 0 |
| 23 | -7 |
| 24 | -8 |
| 25 | 0 |
| 26 | 8 |
| 27 | 9 |
| 28 | 0 |
| 29 | -9 |
| 30 | -10 |
| 31 | 0 |
| 32 | 10 |
| 33 | 11 |
| 34 | 0 |
| 35 | -11 |
| 36 | -12 |
| 37 | 0 |
| 38 | 12 |
| 39 | 13 |
| 40 | 0 |
| 41 | -13 |
| 42 | -14 |
| 43 | 0 |
| 44 | 14 |
| 45 | 15 |
| 46 | 0 |
| 47 | -15 |
| 48 | -16 |
| 49 | 0 |
| 50 | 16 |
| 51 | 17 |
| 52 | 0 |
| 53 | -17 |
| 54 | -18 |
| 55 | 0 |
| 56 | 18 |
| 57 | 19 |
| 58 | 0 |
| 59 | -19 |
| 60 | -20 |
[0,0,0,1,0,-1,-2,0,2,3,0,-3,-4,0,4,5,0,-5,-6,0,6, 7,0,-7,-8,0,8,9,0,-9,-10,0,10,11,0,-11,-12,0,12, 13,0,-13,-14,0,14,15,0,-15,-16,0,16,17,0,-17,-18, 0,18,19,0,-19,-20] |