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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A039769 phi(a(n)) and (a(n)-1) have a common factor but are distinct. 0
9, 15, 21, 25, 27, 28, 33, 35, 39, 45, 49, 51, 52, 55, 57, 63, 65, 66, 69, 70, 75, 76, 77, 81, 85, 87, 91, 93, 95, 99, 105, 111, 112, 115, 117, 119, 121, 123, 124, 125, 129, 130, 133, 135, 141, 143, 145, 147, 148, 153, 154, 155, 159, 161, 165, 169, 171, 172, 175 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

phi(21)=12, gcd(12,20)=4.

CROSSREFS

Cf. A000010.

Sequence in context: A038599 A079364 A160666 * A071904 A014076 A067800

Adjacent sequences:  A039766 A039767 A039768 * A039770 A039771 A039772

KEYWORD

nonn,easy

AUTHOR

Olivier Gerard (olivier.gerard(AT)gmail.com)

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 13 22:36 EST 2012. Contains 205567 sequences.