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A097334
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Sum k=0..n, C(n-k, floor(k/2))2^k.
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4
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1, 3, 3, 7, 19, 31, 59, 135, 259, 495, 1035, 2071, 4051, 8191, 16475, 32679, 65443, 131343, 262059, 523831, 1049203, 2097439, 4192763, 8389575, 16779331, 33550383, 67108683, 134226007, 268427539, 536862271, 1073766299, 2147476455
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f. : (1+2x)/((1-2*x)*(1+x+2*x^2)); a(n)=a(n-1)+4a(n-3).
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MATHEMATICA
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Table[Sum[Binomial[n-k, Floor[k/2]]2^k, {k, 0, n}], {n, 0, 40}] (* or *) LinearRecurrence[{1, 0, 4}, {1, 3, 3}, 40] (* Harvey P. Dale, May 17 2021 *)
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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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