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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A067006 Smallest number for which the totient is divisible by the n-th nontotient number, that is, the n-th term of A007617. 0
7, 11, 29, 19, 23, 53, 29, 31, 103, 191, 43, 47, 101, 53, 81, 59, 311, 67, 103, 71, 149, 191, 79, 83, 173, 181, 283, 197, 101, 103, 107, 121, 229, 709, 367, 311, 127, 131, 269, 137, 139, 569, 293, 149, 151, 229, 463, 317, 163, 167, 1021, 173, 349, 179, 181, 547 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..56.

FORMULA

a(n) = min_{x : mod(x, A007617(n)) = 0}. For all nontotient numbers x, q*x+1 is prime with large enough q and a divisor of phi(q*x+1) = q*x is x, the selected nontotient number.

EXAMPLE

14 = A007617(7) is not totient of any other number, but phi(29) = 28 is divisible with 14 and 29 is the smallest number of which the totient is a multiple of 14, so a(7)=29.

CROSSREFS

Cf. A000010, A007617, A066674-A066678, A067005.

Sequence in context: A002810 A045736 A158807 * A136020 A076304 A122560

Adjacent sequences:  A067003 A067004 A067005 * A067007 A067008 A067009

KEYWORD

nonn

AUTHOR

Labos Elemer, Dec 22 2001

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 November 19 11:09 EST 2019. Contains 329319 sequences. (Running on oeis4.)