

A066418


Numbers n for which phi(n) + antiphi(n)=n.


3



2, 3, 4, 5, 6, 7, 8, 12, 15, 27, 30, 40, 44, 57, 117, 128, 171, 236, 399, 408, 510, 1623, 3597, 3915, 4616, 4684, 7335, 10197, 10768, 14144, 32768, 39387, 76035, 77097
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OFFSET

1,1


COMMENTS

Antiphi(n) (A066452) is the number of numbers coprime to all the antidivisors of n.
See A066272 for definition of antidivisor.


LINKS

Table of n, a(n) for n=1..34.
Jon Perry, Antiphi function [Broken link]
Jon Perry, The Antidivisor [Cached copy]
Jon Perry, The Antidivisor: Even More AntiDivisors [Cached copy]


EXAMPLE

The antidivisors of 7 are 1, 2, 3 and 5. Therefore of the integer 16, only 1 is coprime to 2, 3 and 5, therefore antiphi(7)=1. phi(7)=6, therefore antiphi(7)+phi(7)=7


CROSSREFS

Cf. A066416, A066417, A058838, A066241, A066452.
Sequence in context: A321334 A238084 A211202 * A015845 A030702 A305926
Adjacent sequences: A066415 A066416 A066417 * A066419 A066420 A066421


KEYWORD

nonn,more


AUTHOR

Jon Perry, Dec 28 2001


EXTENSIONS

Edited (Antiphi function link is broken) by Daniel Forgues, Nov 23 2009
a(21)  a(34) from Nathaniel Johnston, Apr 20 2011


STATUS

approved



