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A075657
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Numbers n such that sum of digits (A007953) is a divisor of sum of prime divisors (A008472).
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9
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2, 3, 5, 7, 10, 42, 70, 84, 91, 100, 104, 110, 114, 115, 130, 143, 148, 154, 160, 170, 182, 185, 212, 215, 221, 222, 228, 230, 234, 238, 250, 266, 295, 304, 312, 326, 336, 372, 402, 412, 425, 437, 460, 468, 485, 494, 516, 555, 558, 583, 700, 702, 721, 730
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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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digsum(10) = 1 + 0 = 1, PrimeDivisors(10) = PrimeDivisors(2 *5) = {2,5} and sopf(10) = 2 + 5 = 7 = 7*1.
digsum(154) = 1 + 5 + 4 = 10, PrimeDivisors(154) = PrimeDivisors(2 * 7 * 11) = {2,7,11} and sopf(154) = 2+7+11 = 20 = 2*10.
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MATHEMATICA
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Select[Range[2, 800], Divisible[Total[Select[Divisors[#], PrimeQ]], Total[ IntegerDigits[#]]]&] (* Harvey P. Dale, Sep 23 2012 *)
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PROG
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(Magma) [m:m in [2..730]| &+PrimeDivisors(m) mod &+Intseq(m) eq 0]; // Marius A. Burtea, Jul 11 2019
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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