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 A066428 Numbers with mu = 0 and infinitary MoebiusMu = +1 (sum of binary digits of prime exponents is even). 3
 8, 12, 18, 20, 27, 28, 32, 36, 44, 45, 48, 50, 52, 63, 64, 68, 75, 76, 80, 92, 98, 99, 100, 112, 116, 117, 120, 124, 125, 144, 147, 148, 153, 162, 164, 168, 171, 172, 175, 176, 188, 196, 207, 208, 212, 216, 225, 236, 242, 243, 244, 245, 261, 264, 268, 270, 272 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 EXAMPLE 28 is in this sequence because its prime decomposition is 2^2* 7^1, it is not squarefree and the binary digits of "2" and "1" add up to 2, an even number. MATHEMATICA 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 & ] PROG (PARI) is(n)=my(f=factor(n)[, 2]); #f && vecmax(f)>1 && vecsum(apply(hammingweight, f))%2==0 \\ Charles R Greathouse IV, Oct 15 2015 CROSSREFS Cf. A064179, A066427. Sequence in context: A226527 A212582 A046369 * A228056 A187042 A285508 Adjacent sequences:  A066425 A066426 A066427 * A066429 A066430 A066431 KEYWORD easy,nonn AUTHOR Wouter Meeussen, Dec 27 2001 STATUS approved

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Last modified May 18 10:19 EDT 2021. Contains 343995 sequences. (Running on oeis4.)