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A140467
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Numbers k such that the digits of k are not present in 3k.
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1
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1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 16, 18, 19, 21, 22, 23, 26, 27, 29, 32, 33, 34, 36, 37, 38, 39, 43, 44, 46, 54, 58, 59, 63, 64, 66, 67, 68, 69, 73, 74, 76, 77, 78, 81, 83, 84, 87, 88, 89, 91, 94, 96, 108, 109, 111, 112, 116, 118, 119, 121, 122, 126, 129, 136, 158, 159, 161
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OFFSET
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1,2
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LINKS
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EXAMPLE
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169 is in the sequence because the sets {1,6,9} and {5,0,7} are disjoint.
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MAPLE
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a:=proc(n) local nd, n3d: nd:=convert(convert(n, base, 10), set): n3d:=convert(convert(3*n, base, 10), set): if `intersect`(nd, n3d)={} then n else end if end proc: seq(a(n), n=1..170); # Emeric Deutsch, Jul 20 2008
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MATHEMATICA
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Select[Range[200], Intersection[IntegerDigits[#], IntegerDigits[3*#]]=={}&] (* Harvey P. Dale, Aug 13 2018 *)
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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Jonathan Vos Post, Jun 25 2008
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EXTENSIONS
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STATUS
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approved
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