%I A063752
%S A063752 1,2,3,5,6,7,8,11,13,17,19,21,23,24,27,28,29,31,32,37,41,43,47,53,54,
%T A063752 59,61,67,68,69,71,73,79,83,89,96,97,101,103,107,109,112,113,124,125,
%U A063752 127,128,131,133,137,139,141,149,151,157,163,167,173,179,181,189,191
%N A063752 Numbers n such that cototient(n) is a square.
%H A063752 Harry J. Smith, <a href="b063752.txt">Table of n, a(n) for n=1,...,1000</
               a>
%F A063752 a(n) seems to be asymptotic to c*n*log(n) with c=1.07....(all primes 
               are in the sequence since cototient(p)=1) - Benoit Cloitre (benoit7848c(AT)orange.fr), 
               Sep 08 2002
%o A063752 (PARI) j=[]; for(n=1,400,x=n-eulerphi(n); if(issquare(x),j=concat(j,n))); 
               j
%o A063752 (PARI) { n=0; for (m=1, 10^9, if (issquare(m - eulerphi(m)), write("b063752.txt", 
               n++, " ", m); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), 
               Aug 29 2009]
%Y A063752 Cf. A051953.
%Y A063752 Sequence in context: A140661 A063966 A123030 this_sequence A016741 A006431 
               A151894
%Y A063752 Adjacent sequences: A063749 A063750 A063751 this_sequence A063753 A063754 
               A063755
%K A063752 nonn
%O A063752 1,2
%A A063752 Jason Earls (zevi_35711(AT)yahoo.com), Aug 11 2001