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Search: id:A114520
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| 6, 10, 12, 18, 22, 24, 28, 34, 36, 40, 48, 52, 54, 58, 72, 76, 82, 88, 100, 108, 112, 118, 142, 148, 160, 162, 165, 172, 184, 192, 196, 202, 208, 210, 214, 232, 250, 268, 273, 274, 288, 298, 316, 345, 352, 358, 382, 384, 385, 388, 390, 394, 399, 400, 412, 420
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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24 is a composite. 24 = 2^3 * 3, and 2^3 + 3 = 11, which is prime. So 24 is in the sequence.
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MATHEMATICA
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f[n_] := Plus @@ Power @@@ FactorInteger[n]; Select[Select[Range[425], PrimeQ[f[ # ]] &], ! PrimeQ[ # ] &] (*Chandler*)
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PROGRAM
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(PARI) A008475(n)=local(t); if(n<1, 0, t=factor(n); sum(k=1, matsize(t)[1], t[k, 1]^t[k, 2])); for(i=1, 700, if(!isprime(i)&&isprime(A008475(i)), print1(i, ", "))) (Herrgesell)
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CROSSREFS
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Cf. A008475, A114518, A114521, A047820.
Sequence in context: A066038 A125592 A110085 this_sequence A046288 A101933 A076763
Adjacent sequences: A114517 A114518 A114519 this_sequence A114521 A114522 A114523
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Dec 05 2005
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net) and Lambert Herrgesell (zero815(AT)googlemail.com), Dec 07 2005
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