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A251362
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Numbers n such that n is the concatenation of distinct prime factors of phi(n), in increasing order.
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3
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OFFSET
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1,1
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COMMENTS
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Next term must be greater than 10^8.
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LINKS
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EXAMPLE
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25 is in the sequence since phi(25)=2^2*5, 235741 is in the sequence since phi(235741)=2^4*3^2*5*7*41, and 23517131 is in the sequence since phi(23517131)=2^7*3*5^2*17*131.
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MATHEMATICA
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a251362[n_Integer] := Rest@ Select[Range[n], # ==
FromDigits[Flatten@IntegerDigits[First@Transpose@FactorInteger[EulerPhi[#]]]] &]; a251362[10^6] (* Michael De Vlieger, Dec 03 2014 *)
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CROSSREFS
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KEYWORD
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nonn,base,more,bref
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AUTHOR
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STATUS
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approved
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