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A094147
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Numbers that can be written as sum of squares of two divisors.
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2
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2, 8, 18, 20, 32, 50, 72, 80, 90, 98, 128, 162, 180, 200, 242, 272, 288, 320, 338, 360, 392, 450, 468, 500, 512, 578, 648, 650, 720, 722, 800, 810, 882, 968, 980, 1058, 1088, 1152, 1250, 1280, 1332, 1352, 1440, 1458, 1568, 1620, 1682, 1800, 1872
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OFFSET
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1,1
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LINKS
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EXAMPLE
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6 and 12 are divisors of 180 and 6^2 + 12^2 = 36 + 144 = 180, therefore 180 is a term.
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MATHEMATICA
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aQ[n_] := AnyTrue[n - Divisors[n]^2, IntegerQ[(s = Sqrt[#])] && s>0 && Divisible[n, s] &]; Select[Range[2, 1872], aQ] (* Amiram Eldar, Sep 02 2019 *)
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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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