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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A075594 a(1) = 1, a(2n) = composite, a(2n+1) = prime and sum of two successive terms is alternately prime or composite. 6
1, 4, 2, 9, 3, 8, 7, 6, 19, 10, 5, 12, 13, 16, 11, 18, 17, 14, 31, 22, 23, 20, 29, 24, 41, 26, 37, 30, 47, 32, 43, 28, 53, 36, 59, 38, 61, 40, 71, 42, 73, 34, 83, 44, 67, 46, 79, 48, 97, 52, 89, 50, 103, 54, 101, 56, 109, 58, 107, 60, 127, 64, 113, 66, 137, 62, 139, 72, 131 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Conjecture: a(n+r)= A075593(n) for n > k for some k and r. What is the value of k and r?

This is not a permutation of the positive integers; odd composites > 9 will not appear in the sequence. - Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Feb 06 2006

CROSSREFS

Cf. A075593, A103824, A103825.

Sequence in context: A077809 A201281 A060734 * A076022 A064421 A051494

Adjacent sequences:  A075591 A075592 A075593 * A075595 A075596 A075597

KEYWORD

nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 27 2002

EXTENSIONS

Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net) Feb 16 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 16:36 EST 2012. Contains 206058 sequences.