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A028261
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Numbers whose total number of prime factors (counting multiplicity) is squarefree.
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0
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2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74
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OFFSET
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1,1
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COMMENTS
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The complement is 1, 16, 24, 36, 40, 54, 56, 60, 81, 84, 88, 90, 100.. and contains all entries of A014613, all of A046310, all of A046312 etc. - R. J. Mathar, Dec 15 2015
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LINKS
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PROG
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(PARI) isok(n) = issquarefree(bigomega(n)); \\ Michel Marcus, Aug 31 2013
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Daniel Asimov (dan(AT)research.att.com)
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STATUS
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approved
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