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A015767
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Numbers k such that phi(k) | sigma_9(k).
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10
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1, 2, 3, 6, 12, 14, 15, 30, 35, 38, 42, 54, 56, 70, 78, 87, 95, 105, 114, 126, 135, 140, 147, 168, 174, 182, 190, 209, 210, 215, 216, 222, 248, 258, 264, 266, 270, 285, 294, 297, 315, 342, 357, 378, 418, 420, 430, 447, 455, 456, 494, 518, 540, 546
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OFFSET
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1,2
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COMMENTS
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sigma_9(n) = A013957(n) is the sum of the 9th powers of the divisors of n.
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LINKS
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MATHEMATICA
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Select[Range[500], Divisible[DivisorSigma[9, #], EulerPhi[#]] &] (* Amiram Eldar, Nov 02 2019 *)
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CROSSREFS
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Cf. A020492, A015759, A015761, A015762, A015763, A015764, A015765, A015766, A015768, A015769, A015770, A015771, A015773, A015774, A094470.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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