A075066 Alternately odd and even composite numbers complementing the parity of the index.

9, 4, 15, 6, 21, 8, 25, 10, 27, 12, 33, 14, 35, 16, 39, 18, 45, 20, 49, 22, 51, 24, 55, 26, 57, 28, 63, 30, 65, 32, 69, 34, 75, 36, 77, 38, 81, 40, 85, 42, 87, 44, 91, 46, 93, 48, 95, 50, 99

Offset

1,1

Links

Table of n, a(n) for n=1..49.

Mathematica

Module[{nn=100, ecs, ocs}, ocs=Select[Range[1, nn, 2], CompositeQ]; ecs = Take[ Range[ 4, nn, 2], Length[ocs]]; Riffle[ocs, ecs]] (* Harvey P. Dale, Apr 03 2017 *)

Crossrefs

Cf. A075065.

Cf. A005381.

Sequence in context: A168203 A248310 A133597 * A061363 A100077 A317739

Adjacent sequences: A075063 A075064 A075065 * A075067 A075068 A075069

Keyword

easy,nonn

Author

Amarnath Murthy, Sep 08 2002

Status

approved