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A223077
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Positive integers, written in base 3, with the property that if the base-3 representation is reversed the result is twice the original number.
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3
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1012, 10212, 102212, 1022212, 10121012, 10222212, 101201012, 102222212, 1012001012, 1021210212, 1022222212, 10120001012, 10212010212, 10222222212, 101200001012, 101210121012, 102120010212, 102212102212, 102222222212, 1012000001012, 1012102121012, 1021200010212, 1022120102212, 1022222222212
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OFFSET
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1,1
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COMMENTS
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For the decimal representations of these same numbers see A173951.
Theorem: The number of terms of length n is equal to A103609(n-2).
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LINKS
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MATHEMATICA
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b3rQ[n_]:=FromDigits[Reverse[IntegerDigits[n]], 3]/FromDigits[ IntegerDigits[ n], 3] ==2; Select[FromDigits/@Tuples[{0, 1, 2}, 13], b3rQ]//Quiet (* Harvey P. Dale, Jun 10 2018 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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