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Search: id:A070103
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| A070103 |
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Number of obtuse integer triangles with perimeter n and prime side lengths. |
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+0
7
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| 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 2, 0, 1, 0, 0, 0, 0, 0, 2, 0, 1, 0, 3, 0, 2, 0, 2, 0, 1, 0, 3, 0, 2, 0, 1, 0, 2, 0, 0, 0, 0, 0, 3, 0, 1, 0, 4, 0, 5, 0, 4, 0, 2, 0, 1, 0, 1, 0, 2, 0, 2, 0, 3, 0, 1, 0, 6, 0, 4, 0, 6, 0, 6, 0
(list; graph; listen)
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OFFSET
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1,27
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COMMENT
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a(n) = A070093(n) - A070098(n).
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LINKS
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R. Zumkeller, Integer-sided triangles
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EXAMPLE
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For n=11 there are A005044(11)=4 integer triangles: [1,5,5], [2,4,5], [3,3,5] and [3,4,4]; only one of the two obtuses ([2,4,5] and [3,3,5]) consists of primes, therefore a(11)=1.
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CROSSREFS
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Cf. A070080, A070081, A070082, A070101, A070088, A070105, A070108, A070129.
Sequence in context: A037047 A118917 A045827 this_sequence A113048 A123758 A069846
Adjacent sequences: A070100 A070101 A070102 this_sequence A070104 A070105 A070106
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 05 2002
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