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A308166
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Number of integer-sided triangles with perimeter n such that the smallest side divides the largest.
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1
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0, 0, 1, 0, 1, 1, 1, 0, 3, 1, 1, 1, 3, 2, 3, 0, 3, 3, 3, 2, 5, 2, 2, 2, 6, 4, 5, 2, 4, 4, 4, 3, 8, 5, 5, 3, 6, 5, 6, 3, 7, 7, 7, 6, 9, 4, 4, 4, 10, 8, 9, 6, 8, 8, 8, 5, 10, 7, 7, 7, 11, 10, 11, 6, 11, 9, 9, 8, 11, 8, 8, 8, 14, 13, 14, 9, 11, 9, 9, 8, 15, 11
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OFFSET
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1,9
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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)) * (1 - ceiling((n-i-k)/k) + floor((n-i-k)/k)).
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MATHEMATICA
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Table[Sum[Sum[(1 - Ceiling[(n - i - k)/k] + Floor[(n - i - k)/k]) 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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