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Search: id:A066428
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| A066428 |
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Numbers with mu = 0 and infinitary MoebiusMu = +1 (sum of binary digits of prime exponents is even). |
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+0
2
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| 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; listen)
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OFFSET
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1,1
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EXAMPLE
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28 is in this sequence because its prime decomposition is 2^2* 7^1, it is not square-free, and the binary digits of "2" and "1" add up to 2, an even number.
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MATHEMATICA
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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 & ]
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CROSSREFS
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Cf. A064179, A066427.
Adjacent sequences: A066425 A066426 A066427 this_sequence A066429 A066430 A066431
Sequence in context: A046339 A014612 A046369 this_sequence A054397 A075818 A090738
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KEYWORD
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easy,nonn
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AUTHOR
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Wouter Meeussen (wouter.meeussen(AT)pandora.be), Dec 27 2001
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