OFFSET
0,2
COMMENTS
-a(n) is the Hankel transform of C(n)-C(n+2).
LINKS
Index entries for linear recurrences with constant coefficients, signature (-3,-8,-3,-1).
FORMULA
G.f.: (1+7x+3x^2+x^3)/(1+3x+8x^2+3x^3+x^4); a(n)=(Fibonacci(3*floor((2n+5)/3))/Fibonacci(3))*(4*sin(2*pi*n/3+pi/6)/3+1/3);
a(0)=1, a(1)=4, a(2)=-17, a(3)=17, a(n)=-3*a(n-1)-8*a(n-2)-3*a(n-3)- a(n-4) [From Harvey P. Dale, May 26 2011]
MATHEMATICA
LinearRecurrence[{-3, -8, -3, -1}, {1, 4, -17, 17}, 41] (* or )* CoefficientList[ Series[(1+7x+3x^2+x^3)/(1+3x+8x^2+3x^3+x^4), {x, 0, 40}], x] (* Harvey P. Dale, May 26 2011 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Mar 10 2008
STATUS
approved