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Search: id:A107121
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| A107121 |
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Numbers n such that n=prime(prime(d_1*d_2*...*d_k)) where d_1 d_2 ... d_k is the decimal expansion of n. |
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3
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OFFSET
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1,1
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COMMENT
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If n is in the sequence then pi(n) = prime(d_1*d_2* ...d_k) where d_1 d_2 ... d_k is the decimal expansion of n, so this sequence is a subsequence of A107120. There is no further term up to prime(2*10^7).
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EXAMPLE
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14738827 is in the sequence because 14738827=prime(prime((1*4*7*3*8*8*2*7)).
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MATHEMATICA
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Do[h= IntegerDigits[Prime[m]]; l = Length[h]; If[Min[h] > 0 && m == Prime[Product[h[[k]], {k, l}]], Print[Prime [m]]], {m, 20000000}]
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CROSSREFS
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Cf. A097223, A107120, A107122.
Sequence in context: A107973 A142832 A138956 this_sequence A101734 A059025 A094380
Adjacent sequences: A107118 A107119 A107120 this_sequence A107122 A107123 A107124
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KEYWORD
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base,nonn
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AUTHOR
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Farideh Firoozbakht (f.firoozbakht(AT)math.ui.ac.ir), May 13 2005
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