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A120123
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Numbers n such that n=(d_1*d_2*...*d_k)*phi(d_1+d_2+...+d_k) where d_1 d_2... d_k is the decimal expansion of n.
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2
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OFFSET
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1,2
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COMMENTS
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Conjecture: 139968 is the largest term. Except for the first term, all terms are even. 139968 is also in A120121 & A120122, so it has a very pleasant property (see the Comments lines of A120121).
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LINKS
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EXAMPLE
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34992 is in the sequence because 34992=(3*4*9*9*2)*phi(3+4+9+9+2).
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MATHEMATICA
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Do[If[h = IntegerDigits[n]; l = Length[h]; n == Product[h[[k]], {k, l}]*EulerPhi[Sum[h[[k]], {k, l}]], Print[n]], {n, 50000000}]
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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