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A032125
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"BIK" (reversible, indistinct, unlabeled) transform of 3,3,3,3...
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3
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3, 9, 30, 108, 408, 1584, 6240, 24768, 98688, 393984, 1574400, 6294528, 25171968, 100675584, 402677760, 1610661888, 6442549248, 25770000384, 103079608320, 412317646848, 1649269014528, 6597072912384, 26388285358080, 105553128849408
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Number of solutions (x,y,z) to x+y+z = 2^n, x>=0, y>=0, z>=0, gcd(x,y,z)=1. - Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 22 2002
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LINKS
| C. G. Bower, Transforms (2)
Index to sequences with linear recurrences with constant coefficients, signature (6,-8)
Harvey P. Dale, Table of n, a(n) for n = 1..1000
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FORMULA
| a(n) = 3*2^(n-2)*(2^(n-1)+1). - Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 22 2002
Binomial transform of A067771 (if the offset is changed to 0). - Carl Najafi, Sep 09 2011
G.f. -3*x*(-1+3*x) / ( (4*x-1)*(2*x-1) ). a(n)=3*A007582(n-1). - R. J. Mathar, Sep 11 2011
a(1)=3, a(2)=9, a(n)=6*a(n-1)-8*a(n-2) [From Harvey P. Dale, Jan 01 2012]
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MATHEMATICA
| Table[3*2^(n-2)(2^(n-1)+1), {n, 30}] (* or *) LinearRecurrence[{6, -8}, {3, 9}, 30] (* From Harvey P. Dale, Jan 01 2012 *)
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CROSSREFS
| a(n) = A048240(2^n).
Sequence in context: A128725 A099783 A200074 * A091699 A129167 A151472
Adjacent sequences: A032122 A032123 A032124 * A032126 A032127 A032128
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KEYWORD
| nonn
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AUTHOR
| Christian G. Bower (bowerc(AT)usa.net)
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