|
Search: id:A066452
|
|
| |
|
| 1, 1, 2, 1, 4, 1, 4, 4, 3, 2, 8, 3, 7, 7, 9, 2, 8, 5, 10, 10, 8, 6, 19, 6, 12, 9, 9, 8, 22, 9, 12, 12, 15, 10, 31, 9, 11, 14, 24, 13, 23, 9, 24, 17, 16, 10, 35, 15, 23, 25, 20, 12, 40, 17, 34, 21, 18, 14, 37, 17, 24, 25, 41, 20, 39, 14, 31, 34, 33, 18, 42, 16, 32, 37, 41, 18, 44, 25
(list; graph; listen)
|
|
|
OFFSET
|
2,3
|
|
|
COMMENT
|
anti-phi(n) = the number of integers < n that are not divisible by any anti-divisor of n.
The old definition given for this sequence was: anti-phi(n) = number of integers <= n that are coprime to the anti-divisors of n. However this does not match the entries.
See A066272 for definition of anti-divisor.
|
|
LINKS
|
Diana Mecum, Table of n, a(n) for n = 2..129
Jon Perry, Anti-phi function [Broken link]
Jon Perry, The Anti-divisor [Cached copy]
Jon Perry, The Anti-divisor: Even More Anti-Divisors [Cached copy]
|
|
EXAMPLE
|
10 has anti-divisors 3,4,7. The numbers not divisible by any of 3,4,7 and less than 10 are are 1,2,5. Therefore anti-phi(10)=3.
|
|
CROSSREFS
|
Cf. A058838, A066241.
Adjacent sequences: A066449 A066450 A066451 this_sequence A066453 A066454 A066455
Sequence in context: A024994 A051953 A079277 this_sequence A007104 A102627 A088296
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Jon Perry (perry(AT)globalnet.co.uk), Dec 29 2001
|
|
EXTENSIONS
|
Better definition and more terms from Diana Mecum (diana.mecum(AT)gmail.com), Jul 01 2007
|
|
|
Search completed in 0.002 seconds
|
