OFFSET
0,1
COMMENTS
Sequence identical to its third differences. "Self-transform". Initial terms are transform's coefficients .
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,2).
FORMULA
a(n) = (8/3)*2^n - (2/3)*cos(Pi*n/3) - (16*sqrt(3)/3)*sin(Pi*n/3). - Richard Choulet, Jan 02 2008
G.f.: (2 - 9*x + 18*x^2)/((1-2*x)*(1-x+x^2)). - Philippe Deléham, Dec 29 2008
MATHEMATICA
LinearRecurrence[{3, -3, 2}, {2, -3, 3}, 30] (* or *) CoefficientList[Series[ (-2+9 x-18 x^2)/(-1+3 x-3 x^2+2 x^3), {x, 0, 30}], x] (* Harvey P. Dale, Apr 20 2011 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Paul Curtz, Dec 07 2007
EXTENSIONS
More terms from Philippe Deléham, Dec 29 2008
STATUS
approved