OFFSET
0,4
COMMENTS
Rows sums of A110033.
Conjecture: |a(n)| = Sum_{k=1..n-1} A061646(k). - J. M. Bergot, Jun 10 2013
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,0,-3,1).
FORMULA
G.f.: (1-3x-x^2+2x^3)/((1-x^2)(1-3x+x^2)).
a(n) = a(n-1)-3a(n-3)+a(n-4).
a(n) = Sum_{k=0..n-1} F(k)*F(k+1) - F(2n) + 1.
a(n) = (5+(-1)^n-4*(-1)^n*A098149(n))/10. [R. J. Mathar, Jul 22 2010]
MATHEMATICA
CoefficientList[Series[(-2*z^3 + z^2 + 3*z - 1)/(z^4 - 3*z^3 + 3*z - 1), {z, 0, 100}], z] (* Vladimir Joseph Stephan Orlovsky, Jul 17 2011 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Jul 08 2005
STATUS
approved