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Search: id:A110084
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| A110084 |
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Numbers n with even length such that sigma(n)=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
5
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| 146710, 334552, 12931485, 15734393, 16839254, 20499191, 28661422, 38722820, 43681330, 44463034, 45509442, 55188392, 55938216
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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There is no further term up to 6*10^7.
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EXAMPLE
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45509442 is in the sequence because sigma(55938216)=5^5*9^3*8^2*1^6.
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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 &] == {} && DivisorSigma[1, n]== Product[h[[2j-1]]^h[[2j]], {j, k/2}], Print[n]], {n, 10^8}]
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CROSSREFS
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Cf. A112009, A112010, A112011.
Adjacent sequences: A110081 A110082 A110083 this_sequence A110085 A110086 A110087
Sequence in context: A101202 A004042 A133324 this_sequence A004670 A111044 A015317
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KEYWORD
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base,more,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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