OFFSET
0,1
COMMENTS
a(n) is nonnegative since the real root of x^3-2*x^2+2*x-2 is dominant. - Michael Somos, Feb 28 2007
LINKS
N. J. A. Sloane, Transforms
Index entries for linear recurrences with constant coefficients, signature (2,-2,2).
FORMULA
a(n)=2a(n-1)-2a(n-2)+2a(n-3), a(0)=3, a(1)=2, a(2)=0.
G.f.: (3 - 4*x + 2*x^2)/(1 - 2*x + 2*x^2 - 2*x^3).
MATHEMATICA
CoefficientList[Series[(3-4*x+2*x^2)/(1-2*x+2*x^2-2*x^3), {x, 0, 40}], x]
LinearRecurrence[{2, -2, 2}, {3, 2, 0}, 40] (* Harvey P. Dale, Jan 24 2019 *)
PROG
(PARI) {a(n)= if(n<0, 0, polsym( x^3 -2*x^2 +2*x -2, n) [n+1])} /* Michael Somos, Feb 28 2007 */
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Mario Catalani (mario.catalani(AT)unito.it), Sep 02 2002
STATUS
approved