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A070138
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Number of integer triangles with an integer area having relatively prime sides a, b and c such that a + b + c = n.
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17
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 1, 0, 2, 0, 0, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 3, 0, 1, 0, 1, 0, 2, 0, 1, 0, 0, 0, 1, 0, 1, 0, 2, 0, 0, 0, 5, 0, 0, 0, 0, 0, 3
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OFFSET
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1,36
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COMMENTS
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From Peter Kagey, Jan 30 2018: (Start)
a(k) > 0 if and only if k is in A096468.
Records appear at indices 12, 36, 54, 84, 98, 162, 242, 338, 484, 578, ....
a(2k - 1) = 0 for all integers k > 0.
(End)
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LINKS
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Peter Kagey, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Heronian Triangle.
R. Zumkeller, Integer-sided triangles
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CROSSREFS
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Cf. A051493, A051516, A070088, A070109, A070143, A096468, A239246.
Sequence in context: A208575 A070203 A070201 * A024153 A341523 A079127
Adjacent sequences: A070135 A070136 A070137 * A070139 A070140 A070141
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller, May 05 2002
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EXTENSIONS
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Corrected by T. D. Noe, Jun 17 2004
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STATUS
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approved
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