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A175507
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Numbers such that each digit from 0 to 9 appears at least 7 times in the digits of their divisors.
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1
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7980, 8190, 9360, 10920, 11760, 11880, 12870, 13230, 13860, 14820, 15960, 16380, 16740, 17640, 17940, 18216, 18270, 18360, 18720, 18810, 18900, 19040, 19080, 19140, 19656, 19740, 20196, 20580, 20790, 20880, 21168, 21560, 21840, 22176
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OFFSET
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1,1
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LINKS
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EXAMPLE
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5460 is not in the sequence because the divisors, 1, 2, 3, 4, 5, 6, 7, 10, 12, 13, 14, 15, 20, 21, 26, 28, 30, 35, 39, 42, 52, 60, 65, 70, 78, 84, 91, 105, 130, 140, 156, 182, 195, 210, 260, 273, 364, 390, 420, 455, 546, 780, 910, 1092, 1365, 1820, 2730, 5460, contain the digit 7 only 6 times (namely once in 7, 70, 78, 273, 780 and 2730), which is not enough.
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MATHEMATICA
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fQ[n_] := Block[{s = Transpose@ Tally[ Sort[ Flatten[ IntegerDigits@# & /@ Divisors@ n]]]}, First@ s == {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} && Min@ Last@ s > 6]; k = 1; lst = {}; While[k < 22319, If[ fQ@k, AppendTo[lst, k]]; k++ ]; lst (* Robert G. Wilson v, Jul 31 2010 *)
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CROSSREFS
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KEYWORD
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base,nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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