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A272715
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Numbers equal to the sum of their proper divisors d such that d mod 3 = 2.
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2
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OFFSET
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1,1
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COMMENTS
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The numbers equal to the sum of their proper divisors which are a multiple of 3 are the perfect numbers (A000396) multiplied by 3.
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LINKS
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EXAMPLE
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The proper divisors of 280 which are congruent to 2 mod 3 are 2, 5, 8, 14, 20, 35, 56, and 140. Since their sum is 280, 280 is a term.
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MATHEMATICA
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Select[Range[40000], # == Plus @@ Select[ Most@ Divisors[#], Mod[#, 3] == 2 &] &]
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PROG
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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