for {n,w,c}={7,1,1};{c*Floor[(n-2)/2],(c*Floor[(n-2)/2]-w*(-1)^(c+1))*Mod[n,2],c*(Floor[n/2]-1)(Floor[n/2]-2)-(-1)^(c+1)*w(n-2*(w+1)-Mod[n,2])}