%I A058277
%S A058277 2,3,4,4,5,2,6,6,4,5,2,10,2,2,7,8,9,4,3,2,11,2,2,3,2,9,8,2,2,17,
%T A058277 2,10,2,6,6,3,17,4,2,3,2,9,2,6,3,17,2,9,2,7,2,2,3,21,2,2,7,12,4,
%U A058277 3,2,12,2,8,2,10,4,2,21,2,2,8,3,4,2,3,19,5,2,8,2,2,6,2,31,2,9,10
%N A058277 Number of values of k such that phi(k) = n, where n runs through the 
               values (A002202) taken by phi.
%C A058277 Carmichael (1922) conjectured that the number 1 never appears in this 
               sequence. Sierpinski conjectured and Ford (1998) proved that all 
               integers greater than 1 occur in the sequence. Erdos (1958) proved 
               that if s >= 1 appears in the sequence then it appears infinitely 
               often. - Nick Hobson Nov 04 2006
%D A058277 R. D. Carmichael, Note on Euler's totient function, Bull. Amer. Math. 
               Soc. 28 (1922), pp. 109-110.
%D A058277 P. Erdos, Some remarks on Euler's totient function, Acta Arith. 4 (1958), 
               pp. 10-19.
%D A058277 K. Ford, The Distribution of Totients, Electron. Res. Announc. Amer. 
               Math. Soc. 4 (1998), pp. 27-34.
%D A058277 E. Lucas, Theorie des Nombres, Blanchard 1958.
%H A058277 T. D. Noe, <a href="b058277.txt">Table of n, a(n) for n=1..10000</a>
%H A058277 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               TotientValenceFunction.html">Totient Valence Function</a>
%H A058277 N. Hobson, <a href="http://www.qbyte.org/puzzles/puzzle16.html">Problem 
               152, "Totient valence"</a>
%Y A058277 The nonzero terms of A014197. Cf. A000010, A002202.
%Y A058277 Sequence in context: A108355 A057951 A076410 this_sequence A065852 A088807 
               A036371
%Y A058277 Adjacent sequences: A058274 A058275 A058276 this_sequence A058278 A058279 
               A058280
%K A058277 nonn,easy
%O A058277 1,1
%A A058277 Claude Lenormand (claude.lenormand(AT)free.fr), Jan 05 2001
%E A058277 More terms from Nick Hobson Nov 04 2006