The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A099103 Natural numbers n with more digits than Euler totient phi(n). 1

%I #16 Mar 05 2015 14:38:00

%S 10,12,14,15,16,18,20,24,30,100,102,104,105,106,108,110,111,112,114,

%T 115,116,117,118,119,120,122,123,124,126,128,129,130,132,134,135,136,

%U 138,140,141,142,144,146,147,148,150,152,153,154,156,158,160,162,164,165

%N Natural numbers n with more digits than Euler totient phi(n).

%C This sequence is an indirect comment on the referenced comment of _R. K. Guy_ concerning the occurrence of 301-digit numbers.

%H R. K. Guy, <a href="https://listserv.nodak.edu/cgi-bin/wa.exe?A2=nmbrthry;f9a10ec4.0409">Re: Odd Perfect Numbers</a>, Sep 23 2004 post to NMBRTHRY mailing list.

%e 10 is in the sequence because 2, the number of digits in 10, is more than 1, the number of digits in 4 = phi(10).

%t Select[Range[200], IntegerLength[#] > IntegerLength[EulerPhi[#]] &] (* _Harvey P. Dale_, Dec 14 2010 *)

%Y Cf. A000010, A099102.

%K base,easy,nonn

%O 1,1

%A _Walter Nissen_, Sep 25 2004

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 June 7 10:42 EDT 2024. Contains 373162 sequences. (Running on oeis4.)