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A230539
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a(n) = 3*n*2^(3*n-1).
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3
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0, 12, 192, 2304, 24576, 245760, 2359296, 22020096, 201326592, 1811939328, 16106127360, 141733920768, 1236950581248, 10720238370816, 92358976733184, 791648371998720, 6755399441055744, 57420895248973824, 486388759756013568, 4107282860161892352
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OFFSET
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0,2
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COMMENTS
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Arithmetic derivative of 8^n: a(n) = A003415(8^n).
Sum of reciprocals of a(n), for n>0: (2/3)*log(8/7).
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LINKS
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FORMULA
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G.f.: 12*x/(1-8*x)^2.
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MAPLE
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MATHEMATICA
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Table[3 n 2^(3 n - 1), {n, 0, 20}]
LinearRecurrence[{16, -64}, {0, 12}, 20] (* Harvey P. Dale, Dec 25 2022 *)
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PROG
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(Magma) [3*n*2^(3*n-1): n in [0..20]];
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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