OFFSET
1,3
EXAMPLE
75 is a term because pi(phi(75)) = pi(40) = 12 and phi(pi(75)) = phi(21) = 12;
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.
MAPLE
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, Apr 30 2006
MATHEMATICA
Select[Range[0, 1030], PrimePi@ EulerPhi@# == EulerPhi@ PrimePi@# &] (* Robert G. Wilson v *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), Apr 25 2006
EXTENSIONS
More terms from Robert G. Wilson v and Emeric Deutsch, Apr 27 2006
Edited by Jon E. Schoenfield, Feb 06 2019
STATUS
approved