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A033046
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Sums of distinct powers of 9.
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9
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0, 1, 9, 10, 81, 82, 90, 91, 729, 730, 738, 739, 810, 811, 819, 820, 6561, 6562, 6570, 6571, 6642, 6643, 6651, 6652, 7290, 7291, 7299, 7300, 7371, 7372, 7380, 7381, 59049, 59050, 59058, 59059, 59130, 59131, 59139, 59140, 59778, 59779, 59787
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OFFSET
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0,3
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COMMENTS
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Numbers without any base-9 digits greater than 1.
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LINKS
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FORMULA
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a(n) = Sum_{i=0..m} d(i)*9^i, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
a(2n) = 9*a(n), a(2n+1) = a(2n)+1.
G.f.: (1/(1 - x))*Sum_{k>=0} 9^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017
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MATHEMATICA
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FromDigits[#, 9]&/@Tuples[{1, 0}, 6]//Sort (* Harvey P. Dale, Sep 05 2017 *)
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PROG
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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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EXTENSIONS
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STATUS
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approved
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