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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A058825 Numbers which are both totients and cototients. 1
1, 2, 4, 6, 8, 12, 16, 18, 20, 22, 24, 28, 30, 32, 36, 40, 42, 44, 46, 48, 54, 56, 60, 64, 66, 70, 72, 78, 80, 82, 84, 88, 92, 96, 102, 104, 106, 108, 110, 112, 120, 126, 128, 132, 136, 138, 140, 144, 148, 150, 156, 160, 162, 164, 166, 168, 176, 178, 180, 184, 190 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..10000

FORMULA

Intersection(A002202, A051953).

EXAMPLE

24 is here because 24 = phi(72) = 44-phi(44) = 44-20 = cototient(44).

CROSSREFS

Cf. A000010, A051953, A005277, A005278, A002020, A058763.

Sequence in context: A094109 A090404 A015937 * A087086 A301587 A319796

Adjacent sequences:  A058822 A058823 A058824 * A058826 A058827 A058828

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 04 2001

EXTENSIONS

Offset corrected by Donovan Johnson, Nov 17 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 December 10 18:10 EST 2019. Contains 329901 sequences. (Running on oeis4.)