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A072592
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Even numbers with at least one prime factor of form 4*k+1.
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3
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10, 20, 26, 30, 34, 40, 50, 52, 58, 60, 68, 70, 74, 78, 80, 82, 90, 100, 102, 104, 106, 110, 116, 120, 122, 130, 136, 140, 146, 148, 150, 156, 160, 164, 170, 174, 178, 180, 182, 190, 194, 200, 202, 204, 208, 210, 212, 218, 220, 222, 226, 230, 232, 234, 238
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OFFSET
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1,1
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COMMENTS
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Conjecture: this is exactly the sequence whose terms are twice those of A009003. (This has been verified for all terms<=500.) Compare A009003. - John W. Layman, Mar 12 2008
The conjecture is true. See comments on A008846 and A004613. - Lambert Herrgesell (zero815(AT)googlemail.com), Apr 24 2008
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LINKS
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MATHEMATICA
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opfQ[n_]:=Count[Transpose[FactorInteger[n]][[1]], _?(IntegerQ[ (#-1)/4]&)]>0; Select[Range[2, 250, 2], opfQ] (* Harvey P. Dale, Jun 02 2012 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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