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 A046683 Numbers k such that the sum of squares of divisors of k and sum of cubes of divisors of k are relatively prime. 7
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS It can be shown that this is a subsequence of A028982. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA sdcdQ[n_]:=Module[{d=Divisors[n]}, CoprimeQ[Total[d^2], Total[d^3]]]; Select[ Range[ 20000], sdcdQ] (* Harvey P. Dale, Apr 09 2018 *) PROG (PARI) isok(n) = gcd(sigma(n, 2), sigma(n, 3)) == 1; \\ Michel Marcus, Sep 24 2019 CROSSREFS Cf. A028982, A046678, A046679, A046680, A046681, A046685. Sequence in context: A283315 A024425 A034685 * A065055 A065030 A103321 Adjacent sequences: A046680 A046681 A046682 * A046684 A046685 A046686 KEYWORD nonn AUTHOR Labos Elemer STATUS approved

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Last modified February 21 13:52 EST 2024. Contains 370235 sequences. (Running on oeis4.)