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A230605
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Composite numbers n such that number of non-divisors of n divides sum of non-divisors of n.
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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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a(7) > 10^5.
The terms 20 and 432 are the only composite numbers < 10^5 that are also terms of A023883.
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LINKS
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EXAMPLE
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20 is in sequence because A024816(20) mod A049820(20) = 168 mod 14 = 0.
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PROG
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(PARI) isok(n) = (nnd = n - numdiv(n)) && !isprime(n) && !((n*(n+1)/2-sigma(n)) % nnd); \\ Michel Marcus, Nov 09 2013
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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