login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A053568 Totients of nontotient numbers. 0

%I #14 Nov 20 2017 03:30:36

%S 2,4,6,6,10,12,6,8,16,18,12,22,20,12,18,28,30,20,16,24,36,18,24,40,42,

%T 24,46,42,20,32,52,40,36,58,60,30,36,48,66,32,44,70,72,36,40,36,60,78,

%U 54,82,64,42,56,88,24,72,60,46,72,96,42,60,100,102,48,106

%N Totients of nontotient numbers.

%C See comment at analogous sequence A053474.

%F a(n) = A000010(A007617(n)).

%e If n=19 then no number x such that phi(x) = n exists; however, phi(19) = 18;

%e n=27 is also a nontotient number whose totient is 18.

%o (PARI) lista(nn) = for (n=1, nn, if (!istotient(n), print1(eulerphi(n), ", "))); \\ _Michel Marcus_, Nov 20 2017

%Y Cf. A000010, A007617.

%K nonn

%O 1,1

%A _Labos Elemer_, Jan 17 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)