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A308513
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Sum of the largest side lengths of all integer-sided triangles with perimeter n whose smallest side length is prime.
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1
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0, 0, 0, 0, 0, 2, 3, 3, 7, 8, 14, 10, 17, 12, 25, 20, 36, 31, 50, 35, 63, 47, 79, 62, 98, 80, 120, 87, 130, 94, 140, 101, 161, 120, 185, 142, 212, 167, 255, 209, 304, 257, 359, 289, 397, 324, 438, 362, 482, 403, 546, 439, 589, 478, 635, 520, 703, 585, 777
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OFFSET
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1,6
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LINKS
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FORMULA
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a(n) = Sum_{k=1..floor(n/3)} Sum_{i=k..floor((n-k)/2)} sign(floor((i+k)/(n-i-k+1))) * A010051(k) * (n-i-k).
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MATHEMATICA
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Table[Sum[Sum[(n - i - k) (PrimePi[k] - PrimePi[k - 1]) Sign[Floor[(i + k)/(n - i - k + 1)]], {i, k, Floor[(n - k)/2]}], {k, Floor[n/3]}], {n, 100}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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