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Search: id:A112720
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| A112720 |
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Numbers n such that phi(n)=1^d_1+2^d_2+...+k^d_k where d_1 d_2 ... d_k is the decimal expansion of n. |
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+0
3
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OFFSET
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1,2
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COMMENT
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There is no further term up to 7*10^7.
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EXAMPLE
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phi(11059812)=1^1+2^1+3^0+4^5+5^9+6^8+7^1+8^2 so 11059812 is in
the sequence.
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MATHEMATICA
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Do[d=IntegerDigits[n]; k=Length[d]; If[EulerPhi[n]==Sum[j^d[[j]], {j, k}], Print[n]], {n, 70000000}]
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CROSSREFS
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Cf. A035138, A112718, A112719, A112721.
Adjacent sequences: A112717 A112718 A112719 this_sequence A112721 A112722 A112723
Sequence in context: A099690 A107021 A107022 this_sequence A129059 A129058 A129057
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KEYWORD
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base,fini,more,nonn
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AUTHOR
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Farideh Firoozbakht (f.firoozbakht(AT)math.ui.ac.ir), Sep 17 2005
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