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 A075065 a(1) = 1 and then alternately even and odd composite numbers matching the parity of the index. 1
 1, 4, 9, 6, 15, 8, 21, 10, 25, 12, 27, 14, 33, 16, 35, 18, 39, 20, 45, 22, 49, 24, 51, 26, 55, 28, 57, 30, 63, 32, 65, 34, 69, 36, 75, 38, 77, 40, 81, 42, 85, 44, 87, 46, 91, 48, 93, 50, 95, 52, 99, 54, 105, 56, 111, 58, 115, 60, 117, 62, 119, 64, 121, 66 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..64. MATHEMATICA Module[{nn=150, comps, odds, evens, len}, comps=Complement[Range[nn], Prime[Range[ PrimePi[nn]]]]; odds=Select[ comps, OddQ]; evens=Select[comps, EvenQ]; len=Min[ Length[odds], Length[evens]]; Riffle[Take[odds, len], Take[evens, len]]] (* Harvey P. Dale, Feb 19 2013 *) CROSSREFS Cf. A075066. Sequence in context: A335306 A261023 A171095 * A141553 A095065 A061207 Adjacent sequences: A075062 A075063 A075064 * A075066 A075067 A075068 KEYWORD easy,nonn AUTHOR Amarnath Murthy, Sep 08 2002 EXTENSIONS More terms from Harvey P. Dale, Feb 19 2013 STATUS approved

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Last modified August 12 19:26 EDT 2024. Contains 375113 sequences. (Running on oeis4.)