|
Search: id:A066418
|
|
|
| A066418 |
|
Numbers n for which phi(n) + anti-phi(n)=n. |
|
+0
3
|
|
| 2, 3, 4, 5, 6, 7, 8, 12, 15, 27, 30, 40, 44, 57, 117, 128, 171, 236, 399, 408
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Anti-phi(n) (A066452) is the number of numbers coprime to all the anti-divisors of n.
See A066272 for definition of anti-divisor.
|
|
LINKS
|
Jon Perry, Anti-phi function
Jon Perry, The Anti-divisor [Cached copy]
Jon Perry, The Anti-divisor: Even More Anti-Divisors [Cached copy]
|
|
EXAMPLE
|
The anti-divisors of 7 are 1, 2, 3 and 5. Therefore of the integer 1-6, only 1 is coprime to 2, 3 and 5, therefore anti-phi(7)=1. phi(7)=6, therefore anti-phi(7)+phi(7)=7
|
|
CROSSREFS
|
Cf. A066416, A066417, A058838, A066241, A066452.
Sequence in context: A080543 A119797 A032972 this_sequence A015845 A030702 A033087
Adjacent sequences: A066415 A066416 A066417 this_sequence A066419 A066420 A066421
|
|
KEYWORD
|
nonn,more,easy
|
|
AUTHOR
|
Jon Perry (perry(AT)globalnet.co.uk), Dec 28 2001
|
|
|
Search completed in 0.002 seconds
|
