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A131634
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n-th even semiprime minus n-th odd semiprime.
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3
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-5, -9, -11, -11, -11, -9, -5, -11, -5, 3, 5, 9, 13, 9, 9, 19, 27, 29, 39, 31, 31, 39, 45, 55, 65, 69, 65, 71, 73, 71, 95, 101, 105, 101, 115, 117, 127, 125, 131, 141, 149, 149, 167, 169, 175, 177, 187, 209, 207, 209, 213, 219, 217, 235, 227, 237, 247, 247, 255, 261, 263, 281, 305, 303, 305, 311, 335, 345, 359, 359, 365, 363
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OFFSET
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1,1
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COMMENTS
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Starting with n=10, n-th even semiprime > n-th odd semiprime. Sequence is not monotonic, with general increasing trend.
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LINKS
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FORMULA
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MATHEMATICA
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Module[{semis=Select[Range[1000], PrimeOmega[#]==2&], ev, od, len}, ev = Select[ semis, EvenQ]; od=Select[semis, OddQ]; len=Min[Length[ ev], Length[ od]]; First[#]- Last[#]&/@Thread[{Take[ev, len], Take[od, len]}]] (* Harvey P. Dale, Apr 20 2014 *)
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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