How to find the equivalent resistance for this network of of resisitor using the basic parallel/series combination?
This can be solved with a Star-Mesh transform.
The centre 6 resistors C-H can be replaced by a 4-resistor star, which can be all 1/4 Ohm, if I have it right.

See [this question]
(Under what conditions is the star-mesh transform invertible?) for a more thorough discussion.