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A130593
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Evil semiprimes.
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5
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6, 9, 10, 15, 33, 34, 39, 46, 51, 57, 58, 65, 77, 85, 86, 95, 106, 111, 119, 123, 129, 141, 142, 159, 166, 169, 177, 178, 183, 187, 201, 202, 209, 215, 219, 221, 226, 235, 237, 249, 267
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history;
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OFFSET
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1,1
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COMMENTS
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Products of two (not necessarily distinct) primes such that the product has an even number of 1's in its binary expansion. Non-evil semiprimes are odious (A000069).
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LINKS
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FORMULA
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MATHEMATICA
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Select[Range[300], PrimeOmega[#]==2&&EvenQ[DigitCount[#, 2, 1]]&] (* Harvey P. Dale, Nov 08 2011 *)
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PROG
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(PARI) list(lim)=my(v=List(), t); forprime(p=2, lim\2, forprime(q=2, min(p, lim\p), if(hammingweight(n=p*q)%2, , listput(v, n)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Mar 26 2013
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CROSSREFS
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KEYWORD
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easy,base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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