%I A065154
%S A065154 2,6,12,15,24,30,48,51,60,66,70,78,90,96,102,105,120,130,132,138,140,
%T A065154 150,154,156,165,170,174,180,190,192,204,210,230,234,238,240,246,255,
%U A065154 260,264,266,270,276,280,282,290,300,308,312,315,318,330,340,345,348
%N A065154 Numbers for which Cototient-of-Totient < Totient-of-Cototient.
%H A065154 Harry J. Smith, <a href="b065154.txt">Table of n, a(n) for n=1,...,1000</
a>
%F A065154 A051953[A000010(m)] < A000010[A051953(m)]
%e A065154 m=78 Phi[78]=24, 78-Phi[78]=cototient[78]=54, cototient[24]=24-Phi[24]=24-8=16,
Phi[54]=18 so 16<18,ans m=78 is here.
%t A065154 Flatten[Position[Sign[Table[co[eu[w]]-eu[co[w]], {w, 1, 1000}]], -1]].
%o A065154 (PARI) { n=0; for (m = 2, 10^9, t=eulerphi(m); c=m - t; if (t - eulerphi(t)
< eulerphi(c), write("b065154.txt", n++, " ", m); if (n==1000, return))
) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 13 2009]
%Y A065154 A051953, A000010.
%Y A065154 Sequence in context: A152301 A152389 A114103 this_sequence A143408 A088915
A084790
%Y A065154 Adjacent sequences: A065151 A065152 A065153 this_sequence A065155 A065156
A065157
%K A065154 nonn
%O A065154 1,1
%A A065154 Labos E. (labos(AT)ana.sote.hu), Oct 19 2001
|