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A165442
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Start with m, repeatedly find sum of prime factors until we reach a fixed point, then compute sum of numbers in trajectory except for m and the fixed point. If the resulting sum equals m, adjoin m to the sequence.
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0
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OFFSET
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1,1
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COMMENTS
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No further terms below 10^13. Note that if the sum of the prime factors of a composite number equals itself, then it can only be 4.
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LINKS
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EXAMPLE
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Take 20 as example, the sum of its prime factors is 9, then we move on until we get a prime, 9=3x3, 3+3=6, and 6=2x3, 2+3=5, add all the results in the process, 9+6+5=20. 20=9+6+5, 38=21+10+7, 74=39+16+8+6+5.
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CROSSREFS
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KEYWORD
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nonn,more,bref
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AUTHOR
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K. T. Lee (7x3(AT)21cn.com), Sep 19 2009
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EXTENSIONS
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STATUS
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approved
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