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A046683
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Numbers k such that the sum of squares of divisors of k and sum of cubes of divisors of k are relatively prime.
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7
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1, 2, 4, 9, 18, 25, 36, 100, 121, 225, 289, 484, 529, 841, 900, 1089, 1156, 1681, 2116, 2209, 2601, 2809, 3364, 3481, 4356, 4761, 5041, 6724, 6889, 7225, 7569, 7921, 8836, 10201, 10404, 11236, 11449, 12769, 13225, 13924, 15129, 17161, 18769, 19044
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OFFSET
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1,2
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COMMENTS
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It can be shown that this is a subsequence of A028982.
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LINKS
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MATHEMATICA
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sdcdQ[n_]:=Module[{d=Divisors[n]}, CoprimeQ[Total[d^2], Total[d^3]]]; Select[ Range[ 20000], sdcdQ] (* Harvey P. Dale, Apr 09 2018 *)
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PROG
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(PARI) isok(n) = gcd(sigma(n, 2), sigma(n, 3)) == 1; \\ Michel Marcus, Sep 24 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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