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A072376
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a(n) = a(floor(n/2)) + a(floor(n/4)) + a(floor(n/8)) + ... starting with a(0)=0 and a(1)=1.
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23
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0, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
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OFFSET
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0,5
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LINKS
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FORMULA
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For n > 1: a(n) = msb(n)/2 = 2^floor(log_2(n)-1) = 2*a(floor(n/2)).
G.f.: 1/(2-2x) * (2x-x^2 + Sum_{k>=1} 2^(k-1)*x^2^k). - Ralf Stephan, Apr 18 2003
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MATHEMATICA
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lim = 100; CoefficientList[Series[1/(2 - 2 x) (2 x - x^2 + Sum[ 2^(k - 1) x^2^k, {k, Floor@ Log2@ lim}]), {x, 0, lim}], x] (* Michael De Vlieger, Jan 26 2016 *)
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PROG
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(Python)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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