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A353746
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Numbers k for which phi(sigma(k)) + A064989(sigma(k)) is equal to phi(k) + A064989(k).
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0
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1, 114, 618, 2428, 3868, 11706, 16012, 23946, 2031108, 2938902, 3531102, 10475862, 98250486, 205600756
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OFFSET
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1,2
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COMMENTS
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a(15) > 1442840576, if it exists.
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LINKS
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PROG
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(PARI)
A064989(n) = { my(f=factor(n>>valuation(n, 2))); for(i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f); };
isA353746(n) = { my(s=sigma(n)); ((eulerphi(s)+A064989(s))==(eulerphi(n)+A064989(n))); };
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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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