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Search: id:A097256
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| A097256 |
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Numbers whose set of base 10 digits is {0,9}. |
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+0
2
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| 0, 9, 90, 99, 900, 909, 990, 999, 9000, 9009, 9090, 9099, 9900, 9909, 9990, 9999, 90000, 90009, 90090, 90099, 90900, 90909, 90990, 90999, 99000, 99009, 99090, 99099, 99900, 99909, 99990, 99999, 900000, 900009, 900090, 900099, 900900
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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n such that there exists a permutation p_1, ..., p_n of 1, ..., n such that i + p_i is a power of 10 for every i.
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FORMULA
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a(n) = 9*A007088(n).
a(2n) = 10*a(n), a(2n+1) = a(2n)+9.
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CROSSREFS
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Cf. A001196, A005823, A097251-A097262.
Sequence in context: A094935 A078248 A121029 this_sequence A061478 A061878 A140160
Adjacent sequences: A097253 A097254 A097255 this_sequence A097257 A097258 A097259
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KEYWORD
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nonn,base
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AUTHOR
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Ray Chandler (rayjchandler(AT)sbcglobal.net), Aug 3 2004
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