%I A117483
%S A117483 0,1,3,4,5,8,10,11,17,20,22,30,31,41,50,59,67,75,83,109,127,157,174,179,
%T A117483 191,200,211,241,277,283,331,353,360,367,401,414,431,460,461,475,509,
%U A117483 547,563,587,599,617,709,739,773,797,859,877,919,942,960,967,991,1014
%N A117483 Numbers n for which pi(phi(n))equals phi(pi(n)).
%F A117483 a(n)=pi(phi(n))= phi(pi(n))
%e A117483 a(75)= 12 because pi(phi(75))= pi(40)= 12 and phi(pi(75))= phi(21)=12
%e A117483 a(75)= 12 because pi(phi(75))= pi(40)= 12 and phi(pi(75))= phi(21)=12
%e A117483 Also 0 is a term since pi(phi(0))=pi(0)=0 and phi(pi(0))=phi(0)=0; 1
is a term since pi(phi(1))=pi(1)=0 and phi(pi(1))=phi(0)=0.
%p A117483 with(numtheory): a:=proc(n) if pi(phi(n))=phi(pi(n)) then n else fi end:
seq(a(n),n=0..1350); - Emeric Deutsch (deutsch(AT)duke.poly.edu),
Apr 30 2006
%t A117483 Select[Range[0, 1030], PrimePi@ EulerPhi@# == EulerPhi@ PrimePi@# &]
(* Robert G. Wilson v *)
%Y A117483 Sequence in context: A001602 A087012 A047366 this_sequence A028288 A118250
A079136
%Y A117483 Adjacent sequences: A117480 A117481 A117482 this_sequence A117484 A117485
A117486
%K A117483 nonn
%O A117483 1,3
%A A117483 Luc Stevens (lms022(AT)yahoo.com), Apr 25 2006
%E A117483 More terms from Robert G. Wilson v (rgwv(at)rgwv.com) and Emeric Deutsch
(deutsch(AT)duke.poly.edu), Apr 27 2006
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