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%I #18 Sep 16 2019 08:50:33
%S 4,9,16,24,25,40,49,54,56,60,72,81,84,88,90,96,104,108,121,126,128,
%T 132,135,136,140,150,152,156,160,169,180,184,189,192,198,200,204,220,
%U 224,228,232,234,240,248,250,252,256,260,276,288,289,294,296,297,300,306
%N Numbers with mu = 0 and infinitary MoebiusMu = -1; (sum of binary digits of prime exponents is odd).
%H Amiram Eldar, <a href="/A066427/b066427.txt">Table of n, a(n) for n = 1..10000</a>
%e 54 is in this sequence because its prime decomposition is 2^1 * 3^3, it is not squarefree and the binary digits of "1" and "3" add up to 3, an odd number.
%t iMoebiusMu[ n_ ] := Switch[ MoebiusMu[ n ], 1, 1, -1, -1, 0, If[ OddQ[ Plus@@(DigitCount[ Last[ Transpose[ FactorInteger[ n ] ] ], 2, 1 ]) ], -1, 1 ] ]; Select[ Range[ 400 ], MoebiusMu[ # ]===0 && iMoebiusMu[ # ]===-1 & ]
%o (PARI) is(n)=my(f=factor(n)[,2]); #f && vecmax(f)>1 && vecsum(apply(hammingweight, f))%2 \\ _Charles R Greathouse IV_, Oct 15 2015
%Y Cf. A008683, A064179, A066428.
%K easy,nonn
%O 1,1
%A _Wouter Meeussen_, Dec 27 2001
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