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%I #11 Mar 18 2017 19:20:10
%S 1,6,142,154,157,167,168,169,209,213,214,231,232,235,236,238,239,240,
%T 242,243,244,245,247,248,251,252,257,259,260,261,263,264,266,269,270,
%U 278,279,280,301,318,362,363,364,366,367,368,369,371,372,391,392,402
%N Numbers n such that M(n) = Sum_{i=1..n} mu(phi(i)) where M(n) is the Mertens function A002321(n).
%t mQ[n_]:=Sum[MoebiusMu[i],{i,n}]==Sum[MoebiusMu[EulerPhi[i]],{i,n}]; Select[Range[405],mQ[#] &] (* _Jayanta Basu_, May 22 2013 *)
%K nonn
%O 1,2
%A _Benoit Cloitre_, Feb 19 2002