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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A067887 Composite n such that phi(n+1)<phi(n). 0
9, 21, 25, 27, 33, 35, 39, 45, 49, 51, 55, 57, 63, 65, 69, 75, 77, 81, 85, 87, 91, 93, 95, 99, 111, 115, 117, 119, 121, 123, 125, 129, 133, 135, 141, 143, 145, 147, 153, 155, 159, 161, 169, 171, 175, 177, 183, 185, 187, 189, 195, 201, 203, 205, 207, 209, 213 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

n such that omega(2^n+1)=omega(2^n-1)

CROSSREFS

Sequence in context: A157812 A161326 A111171 * A174870 A141603 A138786

Adjacent sequences:  A067884 A067885 A067886 * A067888 A067889 A067890

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 02 2002

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 16 14:37 EST 2012. Contains 205930 sequences.