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Search: id:A091014
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| A091014 |
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Smallest number having exactly n divisors d such that for some x also d-x and d+x are divisors. |
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+0 2
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| 1, 6, 18, 12, 30, 24, 36, 48, 132, 84, 72, 60, 312, 264, 816, 144, 270, 168, 252, 300, 288, 120, 810, 432, 1224, 180, 1188, 1140, 792, 630, 1152, 240, 2112, 672, 4104, 504, 420, 600, 3672, 540, 1872, 480, 2592, 1584, 900, 5100, 360, 2760, 2040, 1890
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OFFSET
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0,2
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COMMENT
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A091009(a(n))=n and A091009(m)<>n for m<=a(n).
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EXAMPLE
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a(9)=84: the exactly 9 triples of divisors of 84 with the defining property: (1,2,3), (2,3,4), (2,4,6), (1,4,7), (2,7,12), (3,12,21), (7,14,21), (14,21,28) and (14,28,42).
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CROSSREFS
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Sequence in context: A093061 A078741 A129870 this_sequence A097370 A074390 A045857
Adjacent sequences: A091011 A091012 A091013 this_sequence A091015 A091016 A091017
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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), Dec 13 2003
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