OFFSET
0,5
LINKS
Index entries for linear recurrences with constant coefficients, signature (-1,-1,1,1,1).
FORMULA
a(n) = 4*(-1)^floor(2*n/3)*sin(n*Pi/3)*(n*sin(n*Pi/3) - sqrt(3)*cos(n*Pi))/9. - Wesley Ivan Hurt, Sep 24 2017
G.f.: x*(1 + x)*(1 + x^2)/((1 - x)*(1 + x + x^2)^2). - Bruno Berselli, Sep 28 2017
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Sep 30 2007
STATUS
approved