login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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: A218072 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 08:55 EDT 2019. Contains 322241 sequences. (Running on oeis4.)