A308122 Sum of the perimeters of all scalene triangles with perimeter n whose side lengths are squarefree.
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13, 14, 30, 16, 0, 18, 0, 0, 21, 22, 69, 48, 0, 26, 54, 56, 116, 150, 217, 160, 99, 136, 210, 144, 148, 190, 273, 200, 164, 210, 301, 220, 405, 506, 611, 480, 441, 500, 459, 312, 530, 594, 550, 392, 342, 464, 531, 480, 732
Offset: 1
Keywords
Links
- Wikipedia, Integer Triangle
Programs
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Mathematica
Table[n*Sum[Sum[MoebiusMu[i]^2*MoebiusMu[k]^2*MoebiusMu[n - i - k]^2*Sign[Floor[(i + k)/(n - i - k + 1)]], {i, k + 1, Floor[(n - k - 1)/2]}], {k, Floor[(n - 1)/3]}], {n, 100}]