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A103113
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Numbers n such that phi(n)=phi(d_1^d_1)*phi(d_2^d_2)*...*phi(d_k^d_k) where d_1 d_2 ... d_k is the decimal expansion of n.
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2
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1, 113125, 2322432, 21332611, 2115124224, 3111423252, 3412115322, 12451223232, 116222114125, 1141433232511, 2231521231226, 2334121141253, 3222154622111, 4211413132352, 15123362231122, 21123234615111, 32125124213611, 114231133412352, 233152112133612
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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21332611 is in the sequence because phi(21332611)=phi(2^2)*phi(1^1)*phi(3^3)*phi(3^3)*phi(2^2)*phi(6^6)*phi(1^1)*phi(1^1).
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MATHEMATICA
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Do[h=IntegerDigits[m]; l=Length[h]; If[Min[h]>0&&EulerPhi[m]== Product[EulerPhi[h[[k]]^h[[k]]], {k, l}], Print[m]], {m, 200000000}]
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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a(5)-a(17) from Max Alekseyev, May 10 2009, May 05 2010, Aug 22 2013
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STATUS
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approved
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