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A067879
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Numbers n such that sigma(n)=phi(n*omega(n)+1).
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1
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1, 6, 30, 38, 55, 85, 87, 188, 236, 264, 445, 451, 618, 655, 672, 715, 717, 897, 913, 1221, 1265, 1357, 1824, 2095, 2515, 2765, 3009, 3247, 3471, 3605, 3741, 4088, 4117, 4237, 5071, 6747, 7195, 7689, 7701, 8120, 10885, 11577, 12128, 12245, 12549
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OFFSET
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1,2
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COMMENTS
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"Omega(n)" in the definition means the number of distinct prime factors of n, counted without multiplicity. This is implemented in Mathematica as PrimeNu[n] rather than as PrimeOmega[n]. - Harvey P. Dale, Jul 08 2017
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LINKS
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MATHEMATICA
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Select[Range[13000], DivisorSigma[1, #]==EulerPhi[#*PrimeNu[#]+1]&] (* Harvey P. Dale, Jul 08 2017 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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