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A039125
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Numbers whose base-10 representation has the same number of 1's and 7's.
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1
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0, 2, 3, 4, 5, 6, 8, 9, 17, 20, 22, 23, 24, 25, 26, 28, 29, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 43, 44, 45, 46, 48, 49, 50, 52, 53, 54, 55, 56, 58, 59, 60, 62, 63, 64, 65, 66, 68, 69, 71, 80, 82, 83, 84, 85, 86, 88, 89, 90, 92, 93, 94, 95, 96, 98, 99, 107, 127, 137
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OFFSET
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1,2
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LINKS
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MATHEMATICA
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Select[Range[0, 200], DigitCount[#, 10, 1]==DigitCount[#, 10, 7]&] (* Harvey P. Dale, Dec 05 2014 *)
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PROG
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(PARI) isok(n) = my(d=digits(n)); #select(x->(x==1), d) == #select(x->(x==7), d); \\ Michel Marcus, Nov 01 2017
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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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STATUS
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approved
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