%I A005278 M4688
%S A005278 10,26,34,50,52,58,86,100,116,122,130,134,146,154,170,172,186,202,
%T A005278 206,218,222,232,244,260,266,268,274,290,292,298,310,326,340,344,
%U A005278 346,362,366,372,386,394,404,412,436,466,470,474,482,490,518,520
%N A005278 Noncototients: n such that x-phi(x)=n has no solution.
%C A005278 If the strong Goldbach conjecture (every even number>6 is the sum of 
               at least 2 distinct primes p and q) is true, sequence contains only 
               even values. Since p*q-phi(p*q)=p+q-1 and then every odd number can 
               be expressed as x-phi(x). - Benoit Cloitre (benoit7848c(AT)orange.fr), 
               Mar 03 2002
%D A005278 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005278 J. Browkin and A. Schinzel, On integers not of the form n-phi(n), Colloq. 
               Math., 68 (1995), 55-58. [Shows that this sequence is infinite. - 
               Labos E. (labos(AT)ana.sote.hu), Dec 21 1999]
%D A005278 R. K. Guy, Unsolved Problems in Number Theory, B36.
%H A005278 T. D. Noe, <a href="b005278.txt">Table of n, a(n) for n=1..963</a>
%H A005278 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Noncototient.html">Link to a section of The World of Mathematics.</
               a>
%Y A005278 Cf. A006093, A126887. Complement of A051953.
%Y A005278 Sequence in context: A043342 A023715 A045143 this_sequence A157075 A045039 
               A080059
%Y A005278 Adjacent sequences: A005275 A005276 A005277 this_sequence A005279 A005280 
               A005281
%K A005278 nonn,nice
%O A005278 1,1
%A A005278 N. J. A. Sloane (njas(AT)research.att.com).
%E A005278 More terms from Jud McCranie (j.mccranie(AT)comcast.net) 1/97.