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A091296
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Semiprimes with odd digits.
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4
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9, 15, 33, 35, 39, 51, 55, 57, 77, 91, 93, 95, 111, 115, 119, 133, 155, 159, 177, 319, 335, 339, 355, 371, 377, 391, 393, 395, 511, 515, 517, 519, 533, 535, 537, 551, 553, 559, 573, 579, 591, 597, 713, 717, 731, 737, 753, 755, 771, 779, 791, 793, 799, 913, 917
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OFFSET
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1,1
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COMMENTS
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Semiprimes with odd digits are more numerous than those with even digits, cf. A108636.
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LINKS
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MATHEMATICA
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Select[Range[1000], Plus@@Last/@FactorInteger[ # ]==2&&Union[OddQ/@IntegerDigits[ # ]]=={True}&]
PrimeFactorExponentsAdded[n_] := Plus @@ Flatten[ Table[ #[[2]], {1}] & /@ FactorInteger[n]]; Select[ Range[ 938], PrimeFactorExponentsAdded[ # ] == 2 && Union[ OddQ /@ IntegerDigits[ # ]] == {True} &] (* Robert G. Wilson v *)
Select[Range[1000], PrimeOmega[#]==2 && And@@OddQ[IntegerDigits[#]]&] (* Harvey P. Dale, Jul 12 2011 *)
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CROSSREFS
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KEYWORD
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easy,nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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