A168057 Expansion of (1+8x^2+8x^3)/((1-2x)^2*(1+2x+4x^2)).
1, 2, 12, 40, 80, 224, 576, 1152, 2816, 6656, 13312, 30720, 69632, 139264, 311296, 688128, 1376256, 3014656, 6553600, 13107200, 28311552, 60817408, 121634816, 260046848, 553648128, 1107296256, 2348810240, 4966055936, 9932111872
Offset: 0
Links
- G. C. Greubel, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (2,0,8,-16).
Programs
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Mathematica
CoefficientList[Series[(1+8x^2+8x^3)/((1-2x)^2(1+2x+4x^2)), {x,0,50}],x] (* Harvey P. Dale, Mar 24 2011 *) LinearRecurrence[{2, 0, 8, -16}, {1, 2, 12, 40}, 50] (* G. C. Greubel, Jul 08 2016 *)
Formula
a(n) = 2^n*A168056(n).
Comments