8*atan(4*x)
-----------
2
1 + 16*x 32*(1 - 8*x*atan(4*x))
----------------------
2
/ 2\
\1 + 16*x / / 2 \
| 12*x 64*x *atan(4*x)|
256*|-atan(4*x) - --------- + ---------------|
| 2 2 |
\ 1 + 16*x 1 + 16*x /
----------------------------------------------
2
/ 2\
\1 + 16*x /