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A252795
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Numbers m such that 10^m + m is a semiprime.
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1
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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3 is in this sequence because 10^3+3 = 17*59 is semiprime.
7 is in this sequence because 10^7+7 = 941*10627 and these two factors are prime.
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MATHEMATICA
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Select[Range[70], PrimeOmega[10^# + #]==2 &]
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PROG
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(Magma) IsSemiprime:=func<i | &+[d[2]: d in Factorization(i)] eq 2>; [m: m in [1..70] | IsSemiprime(s) where s is 10^m+m];
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CROSSREFS
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Cf. similar sequences listed in A252788.
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KEYWORD
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nonn,more,hard
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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