4*atan(2*x) ----------- 2 1 + 4*x
8*(1 - 4*x*atan(2*x)) --------------------- 2 / 2\ \1 + 4*x /
/ 2 \ | 6*x 16*x *atan(2*x)| 32*|-atan(2*x) - -------- + ---------------| | 2 2 | \ 1 + 4*x 1 + 4*x / -------------------------------------------- 2 / 2\ \1 + 4*x /