OFFSET
0,7
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,-1,1,1,-1,1,-1).
FORMULA
G.f.: x^3*(x^3+x^2-x+1) / ((x-1)^2*(x+1)*(x^2+1)^2). - Colin Barker, Jul 01 2015
a(n) = (cos(n*Pi/2)+sin(n*Pi/2)-1)*((2n-3)*cos(n*Pi/2)+cos(n*Pi)+(2n-3)*sin(n*Pi/2))/8. - Wesley Ivan Hurt, Sep 24 2017
a(n) = floor((n-1)/2)*A021913(n). - Lechoslaw Ratajczak, Sep 22 2021
MATHEMATICA
Array[Floor[(# - 1)/2] Floor[Mod[#, 4]/2] &, 88, 0] (* Michael De Vlieger, Sep 22 2021 *)
PROG
(PARI) concat(vector(3), Vec(x^3*(x^3+x^2-x+1)/((x-1)^2*(x+1)*(x^2+1)^2) + O(x^100))) \\ Colin Barker, Jul 01 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Sep 30 2007
STATUS
approved