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A104886
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Sequence A048138, the number of times that a positive integer occurs as the sum of proper divisors, if Goldbach partitions (two odd primes, which account for most of the values) are ignored.
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0
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0, 1, 1, 0, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 2, 1, 2, 0, 1, 0, 1, 0, 1, 0, 1, 2, 2, 1, 1, 0, 1, 0, 1, 0, 3, 1, 2, 1, 2, 0, 2, 0, 1, 1, 2, 0, 0, 0, 2, 1, 1, 2, 1, 0, 1, 0, 2, 1, 3, 1, 1, 0, 1, 0, 1, 0, 1, 2, 3, 0, 3, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 1, 0, 1, 2, 0, 2, 0, 1, 0, 0, 2
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OFFSET
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2,5
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LINKS
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FORMULA
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a(n) = number of m such that the sum of the proper divisors of m is n, ignoring m if m is the product of two different odd primes.
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EXAMPLE
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a(13)=1 because s(27)=1+3+9 and s(35)=1+5+7=13 however 35's factors 3 and 5 are a Goldbach partition, so 35 is not counted.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Nathan McNew (agreatnate(AT)yahoo.com), Mar 29 2005
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STATUS
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approved
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