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A336596
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Numbers whose number of divisors is divisible by 7.
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2
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64, 192, 320, 448, 576, 704, 729, 832, 960, 1088, 1216, 1344, 1458, 1472, 1600, 1728, 1856, 1984, 2112, 2240, 2368, 2496, 2624, 2752, 2880, 2916, 3008, 3136, 3264, 3392, 3520, 3645, 3648, 3776, 3904, 4032, 4160, 4288, 4416, 4544, 4672, 4800, 4928, 5056, 5103
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OFFSET
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1,1
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COMMENTS
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The asymptotic density of this sequence is 1 - zeta(7)/zeta(6) = 0.0088404638... (Sathe, 1945).
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LINKS
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FORMULA
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EXAMPLE
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64 is a term since A000005(64) = 7 is divisible by 7.
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MAPLE
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q:= n-> is(irem(numtheory[tau](n), 7)=0):
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MATHEMATICA
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Select[Range[5000], Divisible[DivisorSigma[0, #], 7] &]
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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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