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Search: id:A112010
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| A112010 |
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Numbers n with even length such that phi(n)=phi(d_1^d_2*d_3^d_4*...* d_(k-1)^d_k) where d_1 d_2 ... d_k is the decimal expansion of n. |
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+0
4
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| 24, 1064, 2592, 6520, 106434, 145166, 237165, 262535, 372780, 491520, 531765, 546410, 566250, 636352, 12716544, 12806910, 13666320, 15116832, 15408692, 17473715, 21645616, 23473515, 23726640, 23728264, 26722436, 26757024
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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33452293 is in the sequence because phi(33452293)=phi(3^3*4^5*2^2*9^3).
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MATHEMATICA
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Do[h = IntegerDigits[n]; k = Length[h]; If[EvenQ[k] && Select[ Range[k/2], h[[2#-1]] == 0 &] == {} && EulerPhi[n]==EulerPhi [Product[h[[2j-1]]^h[[2j]], {j, k/2}], Print[n]], {n, 31000000}]
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CROSSREFS
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Cf. A110084, A112009, A112011.
Sequence in context: A058810 A129622 A112011 this_sequence A046906 A130552 A114051
Adjacent sequences: A112007 A112008 A112009 this_sequence A112011 A112012 A112013
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KEYWORD
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base,nonn
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AUTHOR
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Farideh Firoozbakht (f.firoozbakht(AT)math.ui.ac.ir), Aug 26 2005
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