%I A067843
%S A067843 5,10,7,10,11,12,35,14,13,22,55,22,19,70,19,22,85,26,77,26,27,110,55,
%T A067843 34,55,38,31,34,119,38,65,44,41,52,65,46,185,154,43,46
%N A067843 Least solution k of phi(k-n)+phi(k+n)=phi(2k).
%e A067843 k = 10 is the smallest solution of phi(k-2)+phi(k+2)=phi(2k). So a(2) 
               = 10.
%t A067843 f[k_] := Module[{i = k + 1}, While[EulerPhi[i - k] + EulerPhi[i + k] 
               != EulerPhi[2 i], i++ ]; i]; Table[f[n], {n, 1, 40}]
%Y A067843 Cf. A067701.
%Y A067843 Sequence in context: A005093 A103697 A104645 this_sequence A109360 A141622 
               A144136
%Y A067843 Adjacent sequences: A067840 A067841 A067842 this_sequence A067844 A067845 
               A067846
%K A067843 nonn
%O A067843 1,1
%A A067843 Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Feb 11 2002