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[N. J. A. Sloane]

no, of course it is there!

phi(0)=1 by convention

(see every book on number theory)

%I A000010 M0299 N0111
%S A000010 1,1,2,2,4,2,6,4,6,4,10,4,12,6,8,8,16,6,18,8,12,10,22,8,20,
%T A000010 12,18,12,28,8,30,16,20,16,24,12,36,18,24,16,40,12,42,20,
%U A000010 24,22,46,16,42,20,32,24,52,18,40,24,36,28,58,16,60,30,36
%N A000010 Euler totient function phi(n): count numbers <= n and prime to n.
%R A000010 AS1 840. MOC 23 682 1969.
%O A000010 1,3
%K A000010 easy,core,nonn
%p A000010 with(numtheory): [seq(phi(n),n=1..100)];
%t A000010 Array[EulerPhi, 100]
%A A000010 njas
%H A000010 <a href="http://www.mathsoft.c

NJAS