Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A089684
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
%I A089684
%S A089684 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,
%T A089684 49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81,83,85,87,89,91,
%U A089684 93,95,97,99,101,103,107,109,111,113,115,117,119,121,123,125,127
%N A089684 Numbers n such that 2*phi(n) > n.
%F A089684 Asymptotic to c*n with c=2.045...
%t A089684 lst={}; Do[If[2*EulerPhi[n]>n, AppendTo[lst, n]], {n, 200}]; lst (T. 
               D. Noe)
%t A089684 Select[ Range[130], 2EulerPhi[ # ] > # &] (from Robert G. Wilson v Jan 
               16 2004)
%Y A089684 Cf. A036798, A067800 (composite n such that 2 phi(n) > n).
%Y A089684 Cf. A036798, the missing odd numbers.
%Y A089684 Sequence in context: A005408 A144396 A060747 this_sequence A105356 A082453 
               A033041
%Y A089684 Adjacent sequences: A089681 A089682 A089683 this_sequence A089685 A089686 
               A089687
%K A089684 nonn
%O A089684 1,2
%A A089684 Benoit Cloitre, Jan 16 2004

    
page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 16 17:18 EST 2009. Contains 170825 sequences.


AT&T Labs Research