OFFSET
0,3
COMMENTS
Second differences of 0, 0, 1, 2, 0, 0, 3, 4 .. .
FORMULA
G.f.: (1+x^4+x^3-x^2+x)/((x+1)*(x^2+1)^2). - Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009
a(n) = (-2*(-1)^n+(7+6*n+3*(-1)^n)*cos(n*Pi/2)+(13-6*n+9*(-1)^n)*sin(n*Pi/2) )/8. - Wesley Ivan Hurt, May 07 2021
CROSSREFS
KEYWORD
sign
AUTHOR
Paul Curtz, Sep 20 2007
STATUS
approved